Fuel Efficiency in Transportation

First Edition, 2011

ISBN 978-93-81157-57-2

© All rights reserved.

Published by: The English Press 4735/22 Prakashdeep Bldg, Ansari Road, Darya Ganj, Delhi - 110002 Email: [email protected] 

Table of Contents Chapter 1- Fuel Efficiency in Transportation Chapter 2 - Fuel Economy in Automobiles Chapter 3 - Fuel Economy-Maximizing Behaviors Chapter 4 - Fuel Efficiency Boosting Technologies Chapter 5 - Specimens for Transport Fuel Efficiency Chapter 6 - Corporate Average Fuel Economy

Chapter- 1

Fuel Efficiency in Transportation

The fuel efficiency in transportation ranges from some hundred kilojoule per kilometre for a bicycle to several megajoule for a helicopter. Efficiency can be expressed in terms of consumption per unit distance per vehicle, consumption per unit distance per passenger or consumption per unit distance per unit mass of cargo transported.

Transportation modes For freight transport, rail and ship transport are generally much more efficient than trucking, and air freight is much less efficient.)

Walking • •

A 140 lb person walking at 3 mi/h requires approximately 80 kcal (330 kJ) of food energy per mile. Given that 1 gallon of gasoline contains about 114,000 BTU (120 MJ) of energy, this converts to roughly 360 MPG.

Bicycling As a relatively light and slow vehicle, with low-friction tires, and an efficient chaindriven drivetrain, the bicycle can be an efficient form of transport. A 140lb (64kg) cyclist riding at 16km/h requires about half the energy per unit distance of walking: 43kcal/mi. This figure depends on the speed and mass of the rider: greater speeds give higher air drag and heavier riders also consume more energy per unit distance. This converts to about 670 MPG. A motorized bicycle such as the Velosolex affords the rider to cycle under human power or with the assistance of a 49 cm3 (3.0 cu in) engine which equates to a range of 160–200

mpg-US (1.5–1.2 L/100 km; 190–240 mpg-imp). Electric pedal assisted bikes run on as little as 1.0 kilowatt-hour per 100 kilometres (0.036 MJ/km; 0.016 kW·h/mi), while maintaining speeds in excess of 30 km/h (19 mph). These best-case figures rely on a human doing 70% of the work, with around 3.6 MJ/100 km (55 BTU/mi) coming from the engine. Including the human energy dramatically changes the quoted efficiency of cycles. This would include the caloric efficiency of human muscle, cardio vascular efficiency, and the energy costs of producing, transporting, packaging and waste disposal of the food itself. Of course, to make a meaningful comparison with motor vehicles the energy costs of producing, transporting, packaging and waste disposal incurred in providing the fuel for motorized vehicles would have to be included in calculating their efficiency.

Automobiles Automobile fuel efficiency is often expressed in volume fuel consumed per one hundred kilometres (i.e., L/100 km) but in distance per volume fuel consumed (i.e., miles per gallon) in the US. This is complicated by the different energy content of fuels (compare petrol and diesel). The Oak Ridge National Laboratory (ORNL) state that the energy content of unleaded gasoline is 115,000 BTU per US gallon (32 MJ/L) compared to 130,500 BTU per US gallon (36.4 MJ/L) for diesel. A second important consideration is the energy costs of producing these fuels. Bio-fuels, electricity and hydrogen, for instance, have significant energy inputs in their production. Because of this, the 50-70% efficiency of hydrogen production has to be combined with the vehicle efficiency to yield net efficiency. A third consideration to take into account is the occupancy rate of the vehicle. As the number of passengers per vehicle increases the consumption per unit distance per vehicle increases. However this increase is slight compared to the reduction in consumption per unit distance per passenger. We can compare, for instance, the estimated average occupancy rate of about 1.3 passengers per car in the San Francisco Bay Area to the 2006 UK estimated average of 1.58. Example consumption figures •

The Volkswagen Polo 1.4 TDI Bluemotion and the Seat Ibiza 1.4 TDI Ecomotion, both rated at 3.8 L/100 km (74 mpg-imp; 62 mpg-US) (combined) are the most fuel efficient cars on sale in the UK as of 22 March 2008.

•

Honda Insight - achieves 48 mpg-US (4.9 L/100 km; 58 mpg-imp) under real-world conditions. Honda Civic Hybrid- regularly averages around 45 mpg-US (5.2 L/100 km; 54 mpg-imp). Toyota Prius - According to the US EPA's revised estimates, the combined fuel consumption for the 2008 Prius is 46 mpg-US (5.1 L/100 km; 55 mpg-imp), making it the most fuel efficient US car of 2008 according to the EPA. In the UK, the

• •

• •

official fuel consumption figure (combined) for the Prius is 4.3 L/100 km (66 mpg-imp; 55 mpg-US). The General Motors EV1 was rated in a test with a charging efficiency of 373 Wh-AC/mile or 23 kWh/100km (translates approximately to 2.6L/100km). The four passenger GEM NER also uses 169 Wh/mile or 10.4 kWh/100 km, which equates to 2.6 kWh/100 km per person when fully occupied, albeit at only 24 mph (39 km/h).

Aircraft A principal determinant of fuel consumption in aircraft is drag, which must be opposed by thrust for the aircraft to progress. Drag is proportional to the lift required for flight, which is equal to the weight of the aircraft. However, beginning at transonic speeds of around Mach 0.85, shockwaves form increasing drag. For supersonic flight, it is difficult to achieve a lift to drag ratio greater than five and fuel consumption is increased in proportion. As induced drag increases with weight, mass reduction, with improvements in engine efficiency and reductions in aerodynamic drag, has been a principal source of efficiency gains in aircraft, with a rule-of-thumb being that a 1% weight reduction corresponds to around a .75% reduction in fuel consumption. Flight altitude affects both parasitic drag and engine efficiency. Jet-engine efficiency increases at altitude up to the tropopause, the temperature minimum of the atmosphere; at lower temperatures, the Carnot efficiency is higher. Jet engine efficiency is also increased at high speeds, but above about Mach 0.85 the airframe aerodynamic losses increase faster. Concorde fuel efficiency comparison

Concorde

Gulfstream G550 business jet

Boeing 747400

passenger miles/imperial gallon

17

19

109

passenger miles/US gallon

14

16

91

16.6

14.8

2.6

Aircraft

litres/passenger 100 km

Passenger airplanes averaged 4.8 L/100 km per passenger (1.4 MJ/passenger-km) (49 passenger-miles per gallon) in 1998. Note that on average 20% of seats are left unoccupied. Jet aircraft efficiencies are improving: Between 1960 and 2000 there was a 55% overall fuel efficiency gain (if one were to exclude the inefficient and limited fleet of the DH Comet 4 and to consider the Boeing 707 as the base case).. Most of the improvements in efficiency were gained in the first decade when jet craft first came into widespread commercial use. Compared to the most advanced turboprop aircraft of the 1950s, the modern aircraft is only marginally more efficient per passenger-mile. Between 1971 and 1998 the fleet-average annual improvement per available seat-kilometre was

estimated at 2.4%. As over 80% of the fully laden take-off weight of a modern aircraft such as the Airbus A380 is craft and fuel, there remains considerable room for future improvements in efficiency. •

Airbus state that their A380 consumes fuel at the rate of less than 3 L/100 km per passenger. CNN reports that the fuel consumption figures provided by Airbus for the A380, given as 2.9 L/100 km per passenger, are "slightly misleading", because they assume a passenger count of 555, but do not allow for any luggage or cargo. Typical occupancy figures are unknown at this time.

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NASA and Boeing are conducting tests on a 500 lb (230 kg) "blended wing" aircraft. This design allows for greater fuel efficiency since the whole craft produces lift, not just the wings.

•

The Sikorsky S-76C++ twin turbine helicopter gets about 1.65 mpg-US (143 L/100 km; 1.98 mpg-imp) at 140 knots (260 km/h; 160 mph) and carries 12 for about 19.8 passenger-miles per gallon (11.9 litres per 100 passenger-kilometres).

•

The Bell 407 single-engine turbine helicopter burns 51 gallons per hour at 120 knots carrying one pilot and six passengers. 2.35 NM per gal for 14.1 passengermiles per gallon. If the pilot is counted as a passenger, it's 16.4 people-miles per gallon. Increased altitudes can yield better fuel rates. It has operated at 47 gal/hr.

•

Concorde the supersonic transport managed about 17 miles to the gallon per passenger; similar to a business jet, but much worse than a subsonic turbofan aircraft.

Ships •

Cunard state that their liner, the RMS Queen Elizabeth 2, travels 49.5 feet per imperial gallon of diesel oil (3.32 m/L or 41.2 ft/US gal), and that it has a passenger capacity of 1777. Thus carrying 1777 passengers we can calculate an efficiency of 16.7 passenger-miles per imperial gallon (16.9 L/100 p·km or 13.9 p·mpg–US).

Trains UK Freight train average about 1.5-2.0 MPG Loaded. Compared with road transport it is very efficient; if lorries did the same trip they would use 70% more fuel than a freight train. Uk Passenger trains average from 8MPG - 12MPG. •

Freight: the AAR claims an energy efficiency of 457 ton-miles per gallon of diesel fuel in 2008

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The East Japan Railway Company claims for 2004 an energy intensity of 20.6 MJ/car-km, or about 0.35 MJ/passenger-km

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a 1997 EC study on page 74 claims 18.00 kWh/train-km for the TGV Duplex assuming 3 intermediate stops between Paris and Lyon. This equates to 64.80 MJ/train-km. With 80% of the 545 seats filled on average this is 0.15 MJ/passenger-km.

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Actual train consumption depends on gradients, maximum speeds and stopping patterns. Data was produced for the European MEET project (Methodologies for Estimating Air Pollutant Emissions) and illustrates the different consumption patterns over several track sections. The results show the consumption for a German ICE High speed train varied from around 19–33 kW·h/km (68–120 MJ/km; 31–53 kW·h/mi). The data also reflects the weight of the train per passenger. For example, the TGV double-deck ‘Duplex’ trains use lightweight materials in order to keep axle loads down and reduce damage to track, this saves considerable energy.

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A Siemens study of Combino light rail vehicles in service in Basel, Switzerland over 56 days showed net consumption of 1.53 kWh/vehicle-km, or 5.51 MJ/vehicle-km. Average passenger load was estimated to be 65 people, resulting in average energy efficiency of 0.085 MJ/passenger-km. The Combino in this configuration can carry as many as 180 with standees. 41.6% of the total energy consumed was recovered through regenerative braking.

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A trial of a Colorado Railcar double-deck DMU hauling two Bombardier Bi-level coaches found fuel consumption to be 128 US gallons (480 l; 107 imp gal) for 144 miles (232 km), or 1.125 mpg-US (209.1 L/100 km; 1.351 mpg-imp). The DMU has 92 seats, the coaches typically have 162 seats, for a total of 416 seats. With all seats filled the efficiency would be 468 passenger-miles per US gallon (0.503 L/100 passenger-km; 562 passenger-mpg-imp).

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Note that intercity rail in the US reports 3.17 MJ/passenger-km which is several times higher than reported from Japan. Independent transportation researcher David Lawyer attributes this difference to the fact that the losses in electricity generation may not have been taken into account for Japan and that Japanese trains have a larger number of passengers per car.

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Modern electric trains like the shinkansen use regenerative braking to return current into the catenary while they brake. This method results in significant energy savings, where-as diesel locomotives (in use on unelectrified railway networks) typically dispose of the energy generated by dynamic braking as heat into the ambient air.

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This Swiss Railroad company SBB-CFF-FFS cites 0.082 kWh per passenger-km for traction.

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AEA carried out a detailed study of road and rail for the United Kingdom Department for Transport. Final report

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Amtrak reports 2005 energy use of 2,935 BTU per passenger-mile (1.9 MJ/passenger-km).

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The Passenger Rail (Urban and Intercity) and Scheduled Intercity and All Charter Bus Industries Technological and Operational Improvements - FINAL REPORT states that "Commuter operations can dissipate more than half of their total traction energy in braking for stops." and that "We estimate hotel power to be 35 percent (but it could possibly be as high as 45 percent) of total energy consumed by commuter railways." Having to accelerate and decelerate a heavy train load of people at every stop is inefficient despite regenerative braking which can recover typically around 20% of the energy wasted in braking.

Buses •

In July 2005, the average occupancy for buses in the UK was stated to be 9.

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The fleet of 244 40-foot (12 m) 1982 New Flyer trolley buses in local service with BC Transit in Vancouver, Canada, in 1994/95 consumed 35454170 kW·h for 12966285 vehicle-km, or 9.84 MJ/vehicle-km. Exact ridership on trolleybuses is not known, but with all 34 seats filled this would equate to 0.32 MJ/passengerkm. It is quite common to see people standing on Vancouver trolleybuses. Note that this is a local transit service with many stops per kilometre; part of the reason for the efficiency is the use of regenerative braking.

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A diesel bus commuter service in Santa Barbara, CA, USA found average diesel bus efficiency of 6.0 mpg-US (39 L/100 km; 7.2 mpg-imp) (using MCI 102DL3 buses). With all 55 seats filled this equates to 330 passenger-mpg, with 70% filled the efficiency would be 231 passenger-mpg. At the typical average passenger load of 9 people, the efficiency is only 54 passenger-mpg and could be half of this figure when many stops are made in urban routes.

Rockets Unlike other forms of transportation, rockets are commonly designed for putting objects into orbit. Once in sufficiently high orbit, objects have almost negligible air drag, and the orbits decay so slowly that a satellite can be still orbiting decades after launch. For these reasons rocket and space propulsion efficiency is rarely measured in terms of distance per unit of fuel, but in terms of specific impulse which gives how much change in momentum (i.e. impulse) can be obtained from a unit of propellant. However, to give a concrete example, NASA's space shuttle fires its engines for around 8.5 minutes, consuming 1,000 tons of solid propellant (containing 16% aluminium) and an additional 2,000,000 litres of liquid propellant (106,261 kg of liquid hydrogen fuel) to lift the 100,000 kg vehicle (including the 25,000 kg payload) to an altitude of 111 km and an orbital velocity of 30,000 km/h. With a specific energy of 31MJ per kg for aluminum

and 143 MJ/kg for liquid hydrogen, this means that the vehicle consumes around 5 TJ of solid propellant and 15 TJ of hydrogen fuel. Once in orbit at 200 km and around 7.8 km/s velocity, the orbiter requires no further fuel. At this altitude and velocity, the vehicle has a kinetic energy of about 3 TJ and a potential energy of roughly 200 GJ. Given the energy input of 20 TJ, the Space Shuttle is about 16% energy efficient at launching the orbiter and payload just 4% efficiency if the payload alone is considered. If the Space Shuttle were used to transport people or freight from a point to another on the Earth, using the theoretical largest ground distance (antipodal) flight of 20,000 km, energy usage would be about 0.04 MJ/km/kg of payload.

Other •

NASA's Crawler-Transporter is used to move the Shuttle from storage to the launch pad. It uses diesel and has one of the highest fuel consumption rates on record, 150 US gallons per mile (350 l/km; 120 imp gal/mi).

International transport comparisons UK Public transport Rail and bus are generally required to serve 'off peak' and rural services, which by their nature have lower loads than city bus routes and inter city train lines. Moreover, due to their 'walk on' ticketing it is much harder to match daily demand and passenger numbers. As a consequence, the overall load factor on UK railways is 35% or 90 people per train : Conversely, Air services work on point-to-point networks between large population centres and are 'pre-book' in nature. Using Yield management overall loads can be raised to around 70-90%. However, recently intercity train operators have been using similar techniques, with loads reaching typically 71% overall for TGV services in France and a similar figure for the UK's Virgin trains services.

US Passenger transportation The US Transportation Energy Data Book states the following figures for Passenger transportation in 2006:

Transport mode Vanpool Efficient Hybrid

Average passengers per vehicle 6.1 1.57

BTU per passenger-mile

MJ per passengerkilometre

1,322 1,659

0.867 1.088

Motorcycles Rail (Intercity Amtrak) Rail (Transit Light & Heavy) Rail (Commuter) Air Cars Personal Trucks Buses (Transit)

1.2

1,855

1.216

20.5

2,650

1.737

22.5

2,784

1.825

31.3 96.2 1.57 1.72 8.8

2,996 3,261 3,512 3,944 4,235

1.964 2.138 2.302 2.586 2.776

US Freight transportation The US Transportation Energy book states the following figures for Freight transportation in 2004: Fuel consumption BTU per short ton mile kJ per tonne kilometre Class 1 Railroads 341 246 Domestic Waterborne 510 370 Heavy Trucks 3,357 2,426 Air freight (approx) 9,600 6,900 Transportation mode

Caveats Comparing fuel efficiency in transportation is like comparing apples and oranges. Here are a few things to consider. Traction energy Metrics produced by the UK Rail and Safety •

There is a distinction between vehicle MPGe and passenger MPGe. Most of these entries cite passenger MPGe even if not explicitly stated. It is important not to compare energy figures that relate to unsimilar journeys. An airline jet cannot be used for an urban commute so when comparing aircraft with cars the car figures must take this into account.

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There is currently no agreed upon method of comparing electric vehicle efficiency to heat engine (fossil fuel) vehicle efficiency. However, current typical emissions and thermal energy consumption can be compared.

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If the issue is rapid investment in new electric mass transit it is important to use emissions associated with the most polluting fuel because increased demand for electricity increases the use of polluting fuel used in generation for the immediate future, as well as low emissions fuels in the case of some countries.

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Systems that re-use vehicles like trains and buses can't be directly compared to vehicles that get parked at their destination. They use energy to return (less full) for more passengers and must sometimes run on schedules and routes with little patronage. These factors greatly affect overall system efficiencies. The energy costs of accumulating load need to be included. In the case of most mass transit distributing and accumulating load over many stops means that passenger kilometres are inherently a small proportion of vehicle kilometres see Transport Energy Metrics, Lessons from the west Coast Main line Modernisation and figures for London Underground in transport statistics for Great Britain 2003. Lessons from the west coast mainline modernisation suggest that long passenger rail should operate at less than 40% capacity utilisation and for London underground the figure is probably less than 15%.

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Most cars run at less than full capacity, with the usual average load being between 1 and 2. Cars are also subject to inefficiencies because of congestion and the need to negotiate road junctions.

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Vehicles are not isolated systems. They usually form a part of larger systems whose design inherently determines energy consumption. Judging the value of transport systems by comparing the performance of their vehicles alone can be misleading. For instance, metro systems may have a poor energy efficiency per passenger kilometre, but their high throughput and low physical footprint makes the existence of high urban population densities viable. Total energy consumption per capita declines sharply as population density increases, since journeys become shorter.

Chapter- 2

Fuel Economy in Automobiles

Fuel consumption monitor from a 2006 Honda Airwave.

A 1916 experiment in creating a fuel-economic automobile in the United States. The vehicle weighed only 135 pounds (61.2 kg) and was an adaptation of a small gasoline engine originally designed to power a bicycle. Fuel usage in automobiles refers to the relationship between distance traveled by an automobile and the amount of fuel consumed. There are no quantities or units for fuel usage defined in the International Standard ISO 80000 Quantities and Units, so the nationally-defined reciprocal quantities fuel economy and fuel consumption are used here.

Units of measure

MPG to L/100km conversion chart: blue: U.S. gal, red: imp gal (UK) The two most common ways to measure automobile fuel usage are: Fuel consumption The amount of fuel used per unit distance; most commonly, litres per 100 kilometres (L/100 km). This measure is used in Europe, China, Canada, Australia and New Zealand. Fuel economy The distance traveled per unit of fuel used; in miles per gallon (mpg) or kilometres per litre (km/L), commonly used in in the UK, U.S. (mpg) and Japan, Korea, India, Pakistan, parts of Africa, The Netherlands, Denmark and Latin America (km/L). If mpg is used, it is important to know which gallon is being referred to; the imperial gallon is about 20% larger than the U.S. gallon. Fuel economy and fuel consumption are reciprocal quantities. To convert either way between L/100 km and miles per U.S. gallon, divide 235 by the number in question; for miles per imperial gallon, divide 282 by either number. For example, to convert from 30 mpg (U.S.) to L/100 km, divide 235 by 30, giving 7.83 L/100 km; or from 10 L/100 km to mpg (U.S.), divide 235 by 10, giving 23.5 mpg. To convert between L/100 km and km/L, divide 100 by the number in question. A related measure is the amount of carbon dioxide produced as a result of the combustion process, typically measured in grams of CO2 per kilometre (CO2 g/km). A petrol

(gasoline) engine will produce around 2.32 kg of carbon dioxide for each litre of petrol consumed (19.4 lb/gal). A typical diesel engine produces 2.66 kg/L (22.23 lb/gal) though typically burns fewer litres per kilometre for an otherwise identical car. Since the CO2 emissions are relatively constant per litre, they are proportional to fuel consumption.

Inverse or reciprocal scale A modest improvement in fuel economy for a relatively inefficient vehicle can provide greater savings in terms of financial cost to the driver and environmental impact than a proportionately larger increase for a more economical vehicle. This is most intuitively demonstrated using the inverse scale — gallons per mile or liters per kilometer. If a driver who travels 15,000 miles (24,000 km) a year switches from a vehicle with 10 mpg to 12 mpg average fuel economy (0.10 gallons per mile to 0.083 gallons per mile), 250 gallons are saved. A similar 20% improvement in exchanging a 30 mpg for a 36 mpg (0.033 gallons per mile for 0.027) vehicle saves only 83 gallons. Because mpg and fuel consumption are inversely related, mpg can cause illusions. Gallons Per Mile is more useful than mpg when comparing the fuel consumption of different cars. One should note that MPG works differently than litres per hundred kilometres. l/100 km denotes a rate of fuel consumption, while MPG is a measure of fuel economy (or 'gas mileage'). If a car uses less fuel, the MPG increases, and l/100 km decreases, but the percentages will not match, because the values are reciprocal. For example, 20% better MPG does not mean 20%, but 16.7% less fuel. This comes from the following calculation: 20% is 1.2 times bigger distance, therefore 100% / 1.2 = 83.3% of the original fuel consumption, or 16.7% less fuel. Because consumption is an inverse function of MPG, MPG can be a misleading indicator of fuel efficiency gains. People intuitively take the difference in MPG when comparing two cars. This leads them to underestimate the savings from small improvements on low MPG cars (e.g., 14 to 20 MPG, which saves twice as much fuel over a given distance as the improvement from 33 to 50 MPG). A measure of gallons per mile (GPM), such as gallons per 100 miles, provides an accurate view of consumption for a given distance of driving. Unlike MPG, the GPM of one car can be subtracted from the GPM of another car to get a direct measure of fuel savings.

Gallons per mile Gallons per mile (GPM) is a way of measuring the fuel efficiency of a vehicle. It conveys the amount of fuel that will be used more intuitively than Miles per gallon, which can be misleading. For example, many people incorrectly believe that the improvement from 34 to 44 MPG saves more fuel than the improvement from 15 to 19 MPG because they look at the difference (or percentage change) between MPG levels. The improvement of 15 to 19 MPG change saves about twice as much fuel as the improvement of 34 to 44 MPG over a given distance of driving. "Gallons per 100 miles"

(GPHM) corrects these illusions. When comparing the fuel savings of different vehicles, GPHM can be subtracted. MPG cannot. Because using "gallons per mile" yields small numbers, it is useful to use a longer distance as the base, such as "gallons per hundred miles" (GPHM) or "gallons per 10,000 miles." Many countries use a measure of volume over distance to measure fuel consumption. The following table shows how MPG translates to "gallons per 100 miles" (GPHM) and gallons per 10,000 miles (GP10K), with small rounding: MPG GPHM GP10K 10 10 1,000 11 9 909 12.5 8 800 14 7 714 16.5 6 606 20 5 500 25 4 400 33 3 303 50 2 200 100 1 100 A focus on fuel consumption makes clear the benefits of removing the most inefficient vehicles, as in the Car Allowance Rebate System program. Seemingly small MPG improvements on inefficient cars saves a large amount of fuel over a given distance of driving. For example, replacing a car that gets 14 MPG with a car that gets 25 MPG saves 3 gallons of fuel every 100 miles. That improvement saves more fuel than can be saved by any improvement to a 33 MPG vehicle. Because a gallon of fuel emits 20 pounds of carbon dioxide, saving 3 gallons of fuel every 100 miles saves 3 tons of carbon dioxide every 10,000 miles of driving.

Fuel economy statistics While the ability of petroleum engines to maximize the transformed chemical energy of the fuel (their fuel efficiency) has increased since the beginning of the automotive era, this has not necessarily translated into increased fuel economy or decreased fuel consumption, which is additionally affected by the mass, shape, and size of the car, and the goals of an automobile's designers, which may be to produce greater power and speed rather than greater economy and range. The choice of car and how it is driven drastically affects the fuel economy. A top fuel dragster can consume 6 U.S. gallons (23 L) of nitromethane for a quarter-mile (400 m)

run in about 4.5 seconds, which comes out to 24 U.S. gallons per mile (5,600 L per 100 km). The other extreme was set by PAC-Car II in the 2005 Eco-Marathon, which managed 5384 kilometres per litre (15,210 mpg-imp; 12,660 mpg-US). Both such vehicles are extremes, and most people drive ordinary cars that typically average 15 to 40 miles per U.S. gallon (19 to 50 miles per imperial gallon) or (5.6 to 15 L per 100 km). However, due to environmental concerns caused by CO2 emissions, new EU regulations are being introduced to reduce the average emissions of cars sold beginning in 2012, to 130 g/km of CO2, equivalent to 4.5 L per 100 km (52 mpg U.S., 63 MPG imperial) for a diesel-fueled car, and 5.0 L per 100 km (47 mpg U.S., 56 MPG imperial) for a gasoline (petrol)-fueled car. It should be borne in mind that the average consumption across the fleet is not immediately directly affected by the new vehicle fuel economy, for example Australia's car fleet average in 2004 was 11.5 L/100 km (20.5 mpgU.S.), compared with the average new car consumption in the same year of 25.3 mpgU.S. New Zealand •

2008

United Kingdom • •

May 2008 August 2008

United States EPA • •

2008 2009

Physics The power to overcome air resistance increases roughly with the cube of the speed, and thus the energy required per unit distance is roughly proportional to the square of speed. Because air resistance increases so rapidly with speed, above about 30 mph (48 km/h), it becomes a dominant limiting factor. Driving at 45 rather than 65 mph (72 rather than 105 km/h) results in about one-third the power to overcome wind resistance, or about one-half the energy per unit distance, and much greater fuel economy can be achieved. Increasing speed to 90 mph (145 km/h) from 65 mph (105 km/h) increases the power requirement by 2.6 times, the energy by 1.9 times, and decreases fuel economy. In real world vehicles the change in fuel economy is less than the values quoted above due to complicating factors. The power needed to overcome the rolling resistance is roughly proportional to the speed, and thus the energy required per unit distance is roughly constant. At very low speeds the

dominant losses are internal friction. A hybrid can achieve greater fuel economy in city driving than on the highway because the engine shuts off when it is not needed to charge the battery and has little to no consumption at stops. In addition, regenerative braking puts energy back into the battery.

Speed and fuel economy studies

1997 fuel economy statistics for various U.S. models Fuel economy at steady speeds with selected vehicles was studied in 2010. The most recent study indicates greater fuel efficiency at higher speeds than earlier studies; for example, some vehicles achieve better mileage at 65 than at 45 mph (72 rather than 105 km/h), although not their best economy, such as the 1994 Oldsmobile Cutlass, which has its best economy at 55 mph (29.1 mpg), and gets 2 mpg better economy at 65 than at 45 (25 vs 23 mpg). All cars demonstrated decreasing fuel economy beyond 65 mph (105 km/h), with wind resistance the dominant factor, and may save up to 25% by slowing from 70 mph (110 km/h) to 55 mph (89 km/h). However, the proportion of driving on high speed roadways varies from 4% in Ireland to 41% in Netherlands. There were complaints when the U.S. National 55 mph (89 km/h) speed limit was mandated that it could lower, instead of increase fuel economy. The 1997 Toyota Celica got 1 mpg better fuel-efficiency at 65 than it did at 55 (43.5 vs 42.5), although almost 5 mpg better at 60 than at 65 (48.4 vs 43.5), and its best economy (52.6 mpg) at only

25 mph (40 km/h). Other vehicles tested had from 1.4 to 20.2% better fuel-efficiency at 55 mph (89 km/h) vs. 65 mph (105 km/h). Their best economy was reached at speeds of 25 to 55 mph.

Differing measuring regimes Identical vehicles can have varying fuel consumption figures listed depending upon the testing methods of the jurisdiction. Lexus IS 250 - petrol 2.5 L 4GR-FSE V6, 204 hp (153 kW), 6 speed automatic, rear wheel drive • • •

Australia (L/100 km) - 'combined' 9.1, 'urban' 12.7, 'extra-urban' 7.0 European Union (L/100 km) - 'combined' 8.9, 'urban' 12.5, 'extra-urban' 6.9 United States (L/100 km) - 'combined' 9.8, 'city' 11.2, 'highway' 8.1

2006–2008 Lexus IS 250 (GSE20; U.S.)

2006–2008 Lexus IS 250 (GSE20; Europe)

Fuel economy standards and testing procedures Gasoline new passenger car fuel efficiency Country 2004 average

2004

People's Republic of China United States

Requirement 2005 2008

Later

6.1 L/100 km 5.7 L/100 km 24.6 mpg 27 mpg (9.5 L/100 km) (8.7 L/100 km) (cars and (cars only)* trucks)*

European Union Japan 8.08 L/100 km Australia CAFE eq none (2002) * highway ** combined

35.5 mpg (6.6 L/100 km) (2016) 5 L/100 km (2012) 6.7 L/100 km CAFE eq (2010) 6.7 L/100 km CAFE eq (2010) (voluntary)

Australia Beginning in October 2008, all new cars will need to be sold with a sticker on the windscreen showing the fuel consumption and the CO2 emissions. Fuel consumption figures are expressed as urban, extra urban and combined. Previously, only the combined number was given. Australia also uses a star rating system, from one to five stars, that combines greenhouse gases with pollution, rating each from 0 to 10 with ten being best. To get 5 stars a combined score of 16 or better is needed, so a car with a 10 for economy (greenhouse) and a 6 for emission or 6 for economy and 10 for emission, or anything in between would get the highest 5 star rating. The lowest rated car is the Ssangyong Korrando with automatic transmission, with one star, while the highest rated was the Toyota Prius hybrid. The Fiat 500, Fiat Punto and Fiat Ritmo as well as the Citroen C3 also received 5 stars. The greenhouse rating depends on the fuel economy and the type of fuel used. A greenhouse rating of 10 requires 60 or less grams of CO2 per km, while a rating of zero is more than 440 g/km CO2. The highest greenhouse rating of any 2009 car listed is the Toyota Prius, with 106 g/km CO2 and 4.4 litres per 100 kilometres (64 mpg-imp; 53 mpgUS). Several other cars also received the same rating of 8.5 for greenhouse. The lowest rated was the Ferrari 575 at 499 g/km CO2 and 21.8 litres per 100 kilometres (13.0 mpgimp; 10.8 mpg-US). The Bentley also received a zero rating, at 465 g/km CO2. The best fuel economy of any year is the 2004–2005 Honda Insight, at 3.4 litres per 100 kilometres (83 mpg-imp; 69 mpg-US).

Europe

Irish fuel economy label. In the European Union and the UK, passenger vehicles are commonly tested using two drive cycles, and corresponding fuel economies are reported as 'urban' and 'extra-urban', in liters per 100 km and (in the UK) in miles per imperial gallon. The urban economy is measured using the test cycle known as ECE-15, introduced by the EEC Directive 90/C81/01 in 1999. It simulates a 4,052 m (2.518 mile) urban trip at an average speed of 18.7 km/h (11.6 mph) and at a maximum speed of 50 km/h (31 mph). The extra-urban cycle or EUDC lasts 400 seconds (6 minutes 40 seconds) at an average speed 62.6 km/h (39 mph) and a top speed of 120 km/h (74.6 mph). EU fuel economy numbers tend to be considerably lower than corresponding US EPA test results for the

same vehicle. For example, the 2011 Honda CR-Z with a five-speed manual transmission is rated 6.1/4.4 l/100 km in Europe and 7.6/6.4 l/100 km in the United States. In the European Union advertising has to show Carbon dioxide (CO2)-emission and fuel consumption data in a clear way as described in the UK Statutory Instrument 2004 No 1661. Since September 2005 a color-coded "Green Rating" sticker has been available in the UK, which rates fuel economy by CO2 emissions: A: <= 100 g/km, B: 100–120, C: 121–150, D: 151–165, E: 166–185, F: 186–225, and G: 226+. Depending on the type of fuel used, for gasoline A corresponds to about 4.1 litres per 100 kilometres (69 mpg-imp; 57 mpg-US) and G about 9.5 litres per 100 kilometres (30 mpg-imp; 25 mpg-US). Ireland has a very similar label, but the ranges are slightly different, with A: <= 120 g/km, B: 121–140, C: 141–155, D: 156–170, E: 171–190, F: 191–225, and G: 226+.

New Zealand Starting on 7 April 2008 all cars of up to 3.5 tonnes GVW sold other than private sale need to have a fuel economy sticker applied (if available) that shows the rating from one half star to six stars with the most economic cars having the most stars and the more fuel hungry cars the least, along with the fuel economy in L/100 km and the estimated annual fuel cost for driving 14,000 km. The stickers must also appear on vehicles to be leased for more than 4 months. All new cars currently rated range from 6.9 litres per 100 kilometres (41 mpg-imp; 34 mpg-US) to 3.8 litres per 100 kilometres (74 mpg-imp; 62 mpg-US) and received respectively from 4.5 to 5.5 stars.

United States

Motor vehicle fuel economy from 1966 to 2008.

U.S. Energy Tax Act The Energy Tax Act of 1978 in the U.S. established a gas guzzler tax on the sale of new model year vehicles whose fuel economy fails to meet certain statutory levels. The tax applies only to cars (not trucks) and is collected by the IRS. Its purpose is to discourage the production and purchase of fuel-inefficient vehicles. The tax was phased in over ten years with rates increasing over time. It applies only to manufacturers and importers of vehicles, although presumably some or all of the tax is passed along to automobile consumers in the form of higher prices. Only new vehicles are subject to the tax, so no tax is imposed on used car sales. The tax is graduated to apply a higher tax rate for lessfuel-efficient vehicles. To determine the tax rate, manufacturers test all the vehicles at their laboratories for fuel economy. The U.S. Environmental Protection Agency confirms a portion of those tests at an EPA lab. EPA testing procedure through 2007 Two separate fuel economy tests simulate city driving and highway driving: the city driving program consists of starting with a cold engine and making 23 stops over a period of 31 minutes for an average speed of 20 mph (32 km/h) and with a top speed of 56 mph (90 km/h); the highway program uses a warmed-up engine and makes no stops, averaging 48 mph (77 km/h) with a top speed of 60 mph (97 km/h) over a 10 mile (16 km) distance. The measurements are then adjusted downward by 10% (city) and 22% (highway) to more accurately reflect real-world results. A weight average of city (55%) and highway (45%) fuel economies is used to determine the tax. In some cases, this tax may only apply to certain variants of a given model; for example, the 2004–2006 captive import version of the Holden Monaro did incur the tax when ordered with the four-speed automatic transmission, but did not incur the tax when ordered with the six-speed manual transmission. Because EPA figures had almost always indicated better efficiency than real-world fuelefficiency, the EPA has modified the method starting with 2008. Updated estimates are available for vehicles back to the 1985 model year. EPA testing procedure: 2008 and beyond

New fuel economy label. As a means of reflecting real world fuel economy more accurately, the EPA adds three new tests that will combine with the current city and highway cycles to determine fuel economy of new vehicles, beginning with the 2008 model year. A high speed/quick acceleration loops lasts 10 minutes, covers 8 miles (13 km), averages 48 mph (77 km/h) and reaches a top speed of 80 mph (130 km/h). Four stops are included, and brisk acceleration maximizes at a rate of 8.46 mph (13.62 km/h) per second. The engine begins warm and air conditioning is not used. Ambient temperature varies between 68 °F (20 °C) to 86 °F (30 °C). The air conditioning test raises ambient temperatures to 95 °F (35 °C), and the vehicle's climate control system is put to use. Lasting 9.9 minutes, the 3.6-mile (5.8 km) loop averages 22 mph (35 km/h) and maximizes at a rate of 54.8 mph (88.2 km/h). Five stops are included, idling occurs 19 percent of the time and acceleration of 5.1 mph/sec is achieved. Engine temperatures begin warm. Lastly, a cold temperature cycle uses the same parameters as the current city loop, except that ambient temperature is set to 20 °F (−7 °C). EPA tests for fuel economy do not include electrical load tests beyond climate control, which may account for some of the discrepancy between EPA and real world fuelefficiency. A 200 W electrical load can produce a 0.4 km/L reduction in efficiency on the FTP 75 cycle test.

Following the efficiency claims made for vehicles such as Chevrolet Volt and Nissan Leaf, the National Renewable Energy Laboratory recommended to use EPA's new vehicle fuel efficiency formula that gives different values depending on fuel used. Meanwhile an Israeli firm last urged the EPA to come up with a three-pronged number that would tell people how much electricity a car uses when it's fully charged, how much electricity it takes to charge the car and how much gas the car uses when its battery is depleted. CAFE standards The Corporate Average Fuel Economy (CAFE) regulations in the United States, first enacted by Congress in 1975, are federal regulations intended to improve the average fuel economy of cars and light trucks (trucks, vans and sport utility vehicles) sold in the U.S. in the wake of the 1973 Arab Oil Embargo. Historically, it is the sales-weighted average fuel economy of a manufacturer's fleet of current model year passenger cars or light trucks, manufactured for sale in the United States. Under Truck CAFE standards 2008– 2011 this changes to a "footprint" model where larger trucks are allowed to consume more fuel. The standards are limited to vehicles under a certain weight, but those weight classes will be expanding in 2011 if current law (as of April 2006) holds. State regulations The states are pre-empted by federal law, and are not allowed to make fuel efficiency standards. However, California has a special dispensation from the Clean Air Act to make emissions standards (which other states may adopt instead of the federal standards). The California Air Resources Board is implementing some legislation that limits greenhouse gas emissions. A legal dispute has emerged over whether this is effectually a fuel efficiency standard.

Energy considerations Since the total force that a vehicle faces (that is the total force opposing the vehicle's motion) multiplied by the distance through which the vehicle travels represents the work that the vehicle's engine must generate, the study of mileage (the amount of energy consumed per unit of distance) requires a detailed analysis of the forces that oppose a vehicle's motion. In terms of physics, Force = rate at which the amount of work generated (energy delivered) varies with the distance travelled, or:

Note: The amount of work generated by the vehicle's power source (energy delivered by the engine) would be exactly proportional to the amount of fuel energy consumed by the engine if the engine's efficiency is the same regardless of power output, but this is not necessarily the case due to the operating characteristics of the internal combustion engine.

For a vehicle whose source of power is a heat engine (an engine that uses heat to perform useful work), the amount of fuel energy that a vehicle consumes per unit of distance (level road) depends upon: 1. The thermodynamic efficiency of the heat engine; 2. The forces of friction within the mechanical system that delivers engine output to the wheels; 3. The forces of friction in the wheels and between the road and the wheels (rolling friction); 4. Other internal forces that the engine works against (electrical generator, air conditioner etc., water pump, engine fan etc.); 5. External forces that resist motion (e.g., wind, rain); 6. Non-regenerative braking force (brakes that turn motion energy into heat rather than storing it in a useful form; e.g., electrical energy in hybrid vehicles).

Energy dissipation in city and highway driving. Ideally, a car traveling at a constant velocity on level ground in a vacuum with frictionless wheels could travel at any speed without consuming any energy beyond what is needed to get the car up to speed. Less ideally, any vehicle must expend energy on overcoming road load forces, which consist of aerodynamic drag, tire rolling resistance, and inertial energy that is lost when the vehicle is decelerated by friction brakes. With ideal regenerative braking, the inertial energy could be completely recovered, but there are few options for reducing aerodynamic drag or rolling resistance other than optimizing the vehicle's shape and the tire design. Road load energy, or the energy demanded at the wheels, can be calculated by evaluating the vehicle equation of motion over a specific driving cycle. The vehicle powertrain must then provide this minimum energy in order to move the vehicle, and will lose a large amount of additional energy in the process of

converting fuel energy into work and transmitting it to the wheels. Overall, the sources of energy loss in moving a vehicle may be summarized as follows: • • • • •

•

•

•

•

Engine efficiency, which varies with engine type, the mass of the automobile and its load, and engine speed (usually measured in RPM). Aerodynamic drag force, which increases roughly by the square of the car's speed, but note that drag power goes by the cube of the car's speed. Rolling friction. Braking, although regenerative braking captures some of the energy that would otherwise be lost. Losses in the transmission. (Manual transmissions can be up to 94% efficient whereas older automatic transmissions may be as low as 70% efficient Automatically controlled shifting of gearboxes that have the same internals as manual boxes will give the same efficiency as a pure manual gearbox plus the bonus of added intelligence selecting optimal shifting points Air conditioning. The power required for the engine to turn the compressor decreases the fuel-efficiency, though only when in use. This may be offset by the reduced drag of the vehicle compared with driving with the windows down. The extra mass of the air conditioning system will cause a slight increase in fuel consumption. Power steering. Older hydraulic power steering systems are powered by a hydraulic pump constantly engaged to the engine. Power assistance required for steering is inversely proportional to the vehicle speed so the constant load on the engine from a hydraulic pump reduces fuel efficiency. More modern designs improve fuel efficiency by only activating the power assistance when needed typically this is done by using either direct electrical power steering assistance or an electrically powered hydraulic pump. Cooling. Older cooling systems used a constantly engaged mechanical fan to draw air through the radiator at a rate directly related to the engine speed. This constant load reduces efficiency. More modern systems use electrical fans to draw additional air through the radiator when extra cooling is required. Electrical systems. Headlights, battery charging, active suspension, circulating fans, defrosters, media systems, speakers, and other electronics can also significantly increase fuel consumption, as the energy to power these devices causes increased load on the alternator. Since alternators are commonly only 4060% efficient, the added load from electronics on the engine can be as high as 3 horsepower (2.2 kW) at any speed including idle. In the FTP 75 cycle test, a 200 watt load on the alternator reduces fuel efficiency by 1.7 mpg. Headlights, for example, consume 110 watts on low and up to 240 watts on high. These electrical loads can cause much of the discrepancy between real world and EPA tests, which only include the electrical loads required to run the engine and basic climate control.

Fuel-efficiency decreases from electrical loads are most pronounced at lower speeds because most electrical loads are constant while engine load increases with speed. So at a lower speed a higher proportion of engine horsepower is used by electrical loads. Hybrid

cars see the greatest effect on fuel-efficiency from electrical loads because of this proportional effect.

Fuel economy-boosting technologies • • • • • • • • • • • • •

• • • • •

• •

Using lighter materials for moving parts such as pistons, crankshaft, gears and alloy wheels Using thinner engine oils that require less energy to circulate Reducing the volume of water-based cooling systems so that engines reach their efficient operating temperature sooner Using coolant additives that increase the thermal efficiency of the cooling system Designing the exterior of the vehicle to reduce aerodynamic drag Replacing tires with low rolling resistance (LRR) models Using lower-friction lubricants (engine oil, transmission fluid, axle fluid) Incorporating Locking torque converters in automatic transmissions to reduce slip and power losses in the converter Using a manual gearbox or continuously variable transmission automatic gearbox instead of epicyclic gearboxes with torque converter couplings Increasing the number of gearbox ratios in manual gearboxes Augmenting a downsized engine with an electric drive system and battery (hybrid vehicles) hybrid electric vehicle Replacing petrol engines with more efficient diesel engines Installing an alternator disconnect and supplying electrical system from deep cycle battery pack that is charged at home (although the added weight of the larger battery would have to be considered in calculating the possible fuel savings from this concept) Automatically shutting off engine when vehicle is stopped (mild hybrid) Recapturing wasted energy while braking (regenerative braking) Recapturing wasted energy in the vehicle suspension The use of two-wheel drive only, on road vehicles not used for towing Optimising other engine combustion strategies: o Optimising engine running temperature by electronic control of the cooling system o Stratified Charge combustion o Lean burn combustion o HCCI (Homogeneous Charge Compression Ignition) combustion o Variable valve timing o Supercharging or twincharging (when coupled with a downsized engine) o Turbocharged Direct Injection diesel engines o Gasoline direct injection petrol engines o Common Rail diesel engines o Variable geometry turbocharging Reducing vehicle weight by using materials such as aluminum, fiberglass, plastic, high-strength steel and carbon fiber instead of mild steel and iron Reducing vehicle weight by improving vehicle packaging and space utilisation to enable downsizing without loss of functionality

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Active highway management (matching speed limits and vehicles allowed to join motorways/freeways to traffic density), to maintain traffic throughput and fuel efficiency.

Future technologies Technologies that may improve fuel efficiency, but are not yet on the market, include: • • • • •

•

Compound engines Two-stroke diesel engines High-efficiency gas turbine engines BMW's Turbosteamer - using the heat from the engine to spin a mini turbine to generate power Vehicle electronic control systems that automatically maintain distances between vehicles on motorways/freeways that reduce ripple back braking, and consequent re-acceleration. Time-optimized piston path, to capture energy from hot gases in the cylinders when they are at their highest temperatures

Many aftermarket consumer products exist that are purported to increase fuel economy; many of these claims have been discredited. In the United States, the Environmental Protection Agency maintains a list of devices that have been tested by independent laboratories and makes the test results available to the public.

Fuel economy data reliability The mandatory publication of the fuel consumption by the manufacturer led some to use dubious practices to reach better values in the past. If the test is on a test stand, the vehicle may detect open doors and adapt the engine control. Also when driven according to the test regime, the parameters may adapt automatically. Test laboratories use a "golden car" that is tested in each one to check that each lab produces the same set of measurements for a given drive cycle. Correctly aligning the vehicle wheels is something that should be normal practice for the vehicle users. Tire pressures and lubricants have to be as recommended by the manufacturer (Higher tire pressures are required on a particular dyno type, but this is to compensate for the different rolling resistance of the dyno, not to produce an unrealistic load on the vehicle). Normally the quoted figures a manufacturer publishes have to be proved by the relevant authority witnessing vehicle/engine tests. A lot of Governments independently test emissions from customer vehicles, and as a final measure can force a recall of all of a particular type of vehicle if the customer vehicles do not fulfil manufacturers' claims within reasonable limits. The expense and bad publicity from such a recall means manufacturers should be very cautious not to publish unrealistic figures. The U.S. Federal government retests 10-15% of models), to make sure that the manufacturer's tests are accurate.

Concerns over EPA estimates For many years critics have claimed that EPA estimated fuel economy figures have been misleading. The primary arguments of the EPA detractors were focused on the lack of real world testing, and the very limited scale (i.e., city or highway). EPA changes in 2008 Partly as a response to these criticisms, the EPA changed their fuel economy rating system in 2008 in an attempt to more adequately address these concerns. Instead of testing simply in two presumed modes, the testing now covers: • • •

Faster speeds and acceleration Air conditioner user Colder outside temperatures

Other attempts to improve MPG accuracy While the new EPA standards may represent an improvement, real world user data may still be the best way to gather and collect accurate fuel economy information.

Fuel economy maximizing behaviors Governments, various environmentalist organizations, and companies like Toyota and Shell Oil Company have historically urged drivers to maintain adequate air pressure in tires and careful acceleration/deceleration habits.

Fuel economy as part of quality management regimes Environmental management systems EMAS as well as good fleet management do include record keeping of the fuel consumption of the fleet. Quality management on top of this uses those figures to steer the measures acting on the fleets. You may check whether procurement, driving, and maintenance in total have contributed to changes in the fleets overall consumption.

Units Miles per gallon (MPG) is a unit of measurement that measures fuel economy in automobiles, that is, how many miles a vehicle can travel on one gallon of fuel. It is used similarly in United States and the United Kingdom, although the U.S. gallon is about 83% of the Imperial gallon used in the UK.

MPG to L/100km conversion chart: blue, liq. gal. (U.S.); red, imp. gal. (UK). Most countries other than the U.S. and UK use the metric units litre (approximately 0.220 Imperial gallons or 0.264 U.S. liquid gallons) and km (approximately 0.621 statute miles). These can be combined to either km/l (efficiency) or l/100 km (consumption). The UK is a special case in this respect, as distances are measured in miles but fuel is sold by the litre. As a result, both MPG and l/100 km are usually quoted for any given vehicle. Note that because the imperial gallon is significantly larger than the U.S. gallon, MPG figures are 20.095% higher in the UK than in the U.S. for the same real fuel economy. U.S. Gallons • • •

1 MPG ≈ 0.425 km/l 235/MPG ≈ l/100 km 1 MPG ≈ 1.201 MPG (Imp)

Imperial gallons • • •

1 MPG ≈ 0.354 km/l 282/MPG ≈ l/100 km 1 MPG ≈ 0.833 MPG (U.S.)

Chapter- 3

Fuel Economy-Maximizing Behaviors

Fuel economy-maximizing behaviors describe techniques that drivers can use to optimize their automobile fuel economy. The energy in fuel consumed in driving is lost in many ways, including engine inefficiency, aerodynamic drag, rolling friction, and kinetic energy lost to braking (and to a lesser extent regenerative braking). Driver behavior can influence all of these.

Terminology Various terms describe drivers using unusual driving techniques to maximize fuel efficiency. A few of these are: •

Hypermilers are drivers who exceed the United States Environmental Protection Agency (EPA) estimated fuel efficiency on their vehicles by modifying their driving habits. The term 'hypermiler' originated from hybrid vehicle driving clubs and noted hypermiler Wayne Gerdes and combines current technology (e.g., real time mileage displays) with driving techniques innovated historically with events such as Mobil Economy Run during the 1930s, gas rationing during World War II, techniques that prevailed during 1973 oil crisis, and methods used globally in markets that endure expensive fuel.

•

Nempimania (also Nenpimania) is an obsession with getting the best fuel economy (or the best only-electric range) possible from a hybrid car. It is derived from the Japanese "nempi" (燃費)--a contraction of nenryōshōhiryō （燃料消費量） meaning fuel economy, and mania, meaning "craze for."

•

Eco-driving covers similar ground in other European marketplaces.

Techniques used to maximize fuel economy

Techniques used to improve fuel economy include basic techniques that can be used by most drivers, and advanced techniques that are more specialized, but can be used to achieve extremely high mileage.

Basic techniques Maintenance Key parameters to maintain are proper tire pressure, and wheel alignment, and engine oil with low-kinematic viscosity referred to as low "weight" motor oil. Inflating tires to the maximum recommended air pressure means that less energy is required to move the vehicle. Under-inflated tires can increase rolling resistance by approximately 1.4 percent for every 1 psi (0.1 bar) drop in pressure of all four tires. Equally important is the scheduled maintenance of the engine (i.e. air filter, spark plug), and addressing any onboard diagnostics codes/malfunctions in the Engine Control Module and related sensors, especially the oxygen sensor. Minimizing mass and improving aerodynamics Drivers can also increase fuel economy by driving lighter and/or lower-drag vehicles and minimizing the amount of people, cargo, tools, and equipment carried in the vehicle. Removing common unnecessary accessories such as roof racks, brush guards, wind deflectors (or "spoilers", where designed for downforce not enhanced flow separation), running boards, push bars, and large/wide tires will improve fuel economy by reducing both weight and aerodynamic drag. Some cars also use a half size spare tire, for weight/cost/space saving purposes. Efficient speeds Maintaining an efficient speed is an important factor in fuel efficiency. Optimal efficiency can be expected while cruising with no stops, at minimal throttle and with the transmission in the highest gear. The optimum speed varies with the type of vehicle, although it is usually reported to be 35 mph (56 km/h) or higher. For instance a 2004 Chevrolet Impala had an optimum at 42 mph (70 km/h), and was within 15% of that from 29 to 57 mph (45 to 95 km/h). The US government 2005 Fuel Economy Guide includes a plot showing the optimum between 50 and 55 mph (89 km/h) for an unspecified vehicle. Drivers of vehicles with fuel-economy displays can check their own vehicles by cruising at different speeds and monitoring the readout. Toyota and Ford hybrids have a threshold speed—around 42 mph (68 km/h) in the case of the Prius—above which the engine must run to protect the transmission system. Below this model-dependent speed, the car will automatically switch between either batterypowered mode or engine power with battery recharge where the Prius can achieve over 90mpg. These hybrids typically get their best fuel efficiency below this model-dependent threshold speed. Coasting can be achieved by using Neutral transmission range. The Honda IMA vehicles have a limited, battery-only, powered capability, although after-

market modifications have made the Insight capable of running in electric only-mode. They achieve higher fuel economy. The GM hybrids have an engine auto-stop when halted. As of January 2007, they have no battery-only, powered capability. Road capacity affects speed and therefore fuel efficiency as well. Studies have shown speeds just above 45 mph (72 km/h) allow greatest throughput when roads are congested. Individual drivers can improve their fuel efficiency and that of others by avoiding roads and times where traffic slows to below 45 mph (72 km/h). Communities can improve fuel efficiency by adopting policies to prevent or discourage drivers from entering traffic that is approaching the point where speeds are slowed below 45 mph (72 km/h). Congestion pricing is based on this principle; it raises the price of road access at times of higher usage, to prevent cars from entering traffic and lowering speeds below efficient levels. Note, however, that maximizing throughput and fuel efficiency per vehicle mile traveled does not necessarily minimize total fuel consumption, because with maximum throughput the total vehicle-miles traveled (VMT) may be increased compared to a situation in which congestion reduces throughput. Choice of gear (manual transmissions) Engine efficiency varies with speed and torque, as can be seen in a plot of brake specific fuel consumption. The optimum efficiency point is around 1750 rpm, and 90% of maximum torque at that speed, for this turbo-diesel engine. For driving at a steady speed, one cannot choose any operating point for the engine—rather there is a specific amount of power needed to maintain the chosen speed. A manual transmission lets the driver choose between several points along the curve. In the turbo diesel example, one can see that too low a gear will move the engine into a high-rpm, low-torque region in which the efficiency drops off rapidly, and thus best efficiency is achieved near the higher gear. In a gasoline engine, efficiency typically drops off more rapidly than in a diesel because of throttling losses, and the trend discussed here is even more dramatic. Because cruising at an efficient speed uses much less than the maximum power of the engine, the optimum operating point for cruising at low power is typically at very low engine speed, around or below 1000 rpm. This is far lower than the above mentioned 1750 rpm. This explains the usefulness of very high "overdrive" gears for highway cruising. For instance, a small car might need only 10 -15 HP to cruise at 60 mph (97 km/h). It is likely to be geared for 2500 rpm or so at that speed, yet for maximum economy the engine should be running at about 1000 rpm to generate that power as efficiently as possible for that engine (although the actual figures will vary by engine and vehicle). Acceleration and deceleration (braking) Fuel efficiency varies with the vehicle. Fuel efficiency during acceleration generally improves as RPM increases until a point somewhere near peak torque (brake specific fuel consumption.) However, accelerating too quickly without paying attention to what is ahead may require braking and then after that, additional acceleration. Experts recommend accelerating quickly, but smoothly.

Generally, fuel economy is maximized when acceleration and braking are minimized. So a fuel-efficient strategy is to anticipate what is happening ahead, and drive in such a way so as to minimize acceleration and braking, and maximize coasting time. The need to brake in a given situation is in some cases based on unpredictable events which require the driver to slow or stop the vehicle at a fixed distance ahead. Traveling at higher speeds results in less time available to let up on the accelerator and coast. Also the kinetic energy is higher, so more energy is lost in braking. At medium speeds, the driver has more freedom and can elect to accelerate, coast or decelerate depending on whichever is expected to maximize overall fuel economy. Traveling at posted speeds allows for best civil planning and should allow drivers to best take advantage of traffic signal timing. While approaching a red signal, drivers may choose to "time a traffic light" by easing off the throttle, or braking early if necessary, far before the signal. For example, a driver who is approaching a red light should adjust vehicle speed in advance, such that the vehicle arrives at the intersection when the light is green. It is also important to account for the time it takes for the stopped traffic at the light to start moving again. In theory, the ideal situation is the driver slowing immediately to the calculated speed that allows the car to be barely behind the car in front as that vehicle is accelerating from the light. If the driver does this the instant the red light is recognized, this will result in the vehicle having maximum speed, and kinetic energy, as it reaches the intersection. This means that energy lost to braking is as little as possible. Instead of coasting up to the light and stopping, the driver will now be traveling at a slower speed for a longer time, allowing the light to turn green before he arrives. The driver will never have to fully stop, as accelerating from just a few mph is much more efficient than from a full stop. Using this practice during periods of traffic congestion may affect other drivers and the overall effect is not obvious. Another problem with this technique is that some traffic lights (usually on minor roads where they intersect major roads) are not timed but triggered. They will stay red until a car arrives at the intersection. In this situation, the optimum strategy may be difficult to determine. Conventional brakes dissipate kinetic energy as heat, which is irrecoverable. Regenerative braking, used by hybrid/electric vehicles, recovers some of the kinetic energy, but some energy is lost in the conversion, and the braking power is limited by the battery's maximum charge rate and efficiency. Coasting or gliding The alternative to acceleration and braking is coasting, i.e. gliding along without propulsion. Coasting is an efficient means of slowing down, because kinetic energy is dissipated as aerodynamic drag and rolling resistance, which must always be overcome by the vehicle during travel. When coasting with the engine running and manual transmission in neutral, or clutch depressed, there will still be some fuel consumption due to the engine needing to maintain idle engine speed. While coasting with the engine

running and the transmission in gear, most cars' engine control unit with fuel injection will cut off fuel supply, and the engine will continue running, being driven by the wheels. Compared to coasting in neutral, this has an increased drag, but has the added safety benefit of being able to react in any sudden change in a potential dangerous traffic situation, and being in the right gear when acceleration is required. Anticipation A driver may further improve economy by anticipating the movement of other traffic users. For example, a driver who stops quickly, or turns without signaling, reduces the options another driver has for maximizing his performance. By always giving road users as much information about his intentions as possible, a driver can help other road users reduce their fuel usage. Similarly anticipation of road features such as traffic lights can reduce the need for excessive braking and acceleration. Fuel type It is commonly believed that efficiency of a gasoline engine is related to the fuel's octane level; however, this is not true in most situations. Octane rating is only a measure of the fuel's propensity to cause an engine to "ping"; this ping is due to "pre-combustion", which occurs when the fuel burns too rapidly (before the piston reaches top dead center). Higher-octane fuels burn more slowly at high pressures. For the vast majority of vehicles (i.e. vehicles with "standard" compression ratios), standard-octane fuel will work fine and not cause pinging. Using high-octane fuel in a vehicle that does not need it is generally considered an unnecessary expense, although Toyota has measured slight differences in efficiency due to octane number even when knock is not an issue. All vehicles built since 1996 are equipped with OBD2 and most will have knock sensors that will automatically adjust the timing if and when ping is detected, so low-octane fuel can be used in an engine designed for high octane, with some reduction in efficiency and performance. If the engine is designed for high octane then higher-octane fuel will result in higher efficiency and performance under certain load and mixture conditions. For other vehicles that have problems with ping, it may be due to a maintenance problem, such as carbon buildup inside the cylinder, using spark plugs with the improper heat range or ignition timing problems. In such cases, higher-octane fuel may help, but this is an expensive fix; proper repair might make more long-term sense. There is slightly less energy in a gallon of high-octane fuel than low-octane. Ping is detrimental to an engine; it will decrease fuel economy and will damage the engine over time. Trip computer Modern hybrids come with built-in trip computers which display real-time fuel economy (MPG), which helps the driver adjust driving habits. Most gasoline powered vehicles do not have this as a standard option (although some luxury vehicles do), however most vehicles produced after 1996, have one of three standardized interfaces for "on-board diagnostics", which provides information including the rate of fuel consumption, and the vehicle speed. This streaming data is sufficient to calculate the real-time fuel economy.

Generic aftermarket or "add-on" products are available, such as the "ScanGauge" or "DashDyno SPD", which will connect to a vehicle's onboard computer, read the real-time information, and calculate and display the instantaneous fuel economy. This information assists the driver by displaying the fuel consumption. This provides a general indicator to the driver who can then infer in real-time how driving techniques affect gas mileage. This can help the astute driver to learn how to drive more efficiently. However, such a device does not do all the work for the driver. The device only measures fuel consumption and fuel economy. It does not indicate braking statistics, for example, nor does it teach a driver methods to minimize fuel consumption.

Advanced techniques These are less broadly applicable, some may compromise safety and possibly be illegal in some territories. Burn and coast Burn and coast is also known as pulse and glide. This method consists of accelerating to a given speed (the "burn" or "pulse"), followed by a period of coasting (or "gliding") down to a lower speed, at which point the "burn" is reiterated. Coasting is most efficient when the engine is not running, although some gains can be realized with the engine on (to maintain power to brakes, steering and accessories) and the vehicle in neutral, or even with the vehicle remaining in gear. If a manual transmission vehicle coasts with the engine off, it is typically re-started by popping the clutch. The engine control units of some vehicles command a richer fuel setting immediately after the starter is activated, so the bump-start manual transmission vehicle will typically achieve the best fuel economy gains. Some hybrid vehicles are well-suited to performing the burn and coast. In a seriesparallel hybrid, the internal combustion engine and charging system can be shut off for the glide by simply manipulating the accelerator. For coasting in gear, a later-model vehicle with a fuel-injected engine will realize more gains from the burn and coast technique than older carbureted engines because the engine control units in most fuel-injected engines will cut fuel to the engine when the car is in gear, the throttle is closed and the engine is running faster than idle speed. This is sometimes referred to as "deceleration fuel cut off". This will often engage while a car is coasting down a hill and is common in both automatic and manual transmission vehicles, although the particular engine speeds at which it will engage vary. Auto-stop, forced stop, and draft-assisted forced stop In the auto-stop maneuver, the vehicle's transmission is put in neutral, the engine is turned off (a "forced stop"), and the vehicle coasts to a stop.

Warning: It should be noted that turning a vehicle's ignition off while moving will turn power steering off, can damage an automatic transmission, will disable ABS braking and can disable power brake assist. This may in turn prevent you from avoiding an accident or from driving the car safely if you are not used to driving in this manner. It is possible to coast in neutral with either a manual or automatic transmission. Modern automatic transmissions/transaxles depend on an engine driven fluid pump for lubrication and coasting with the engine off may lead to damage or failure of the transmission. To perform the maneuver, the driver shifts into neutral, and then keys the ignition back to the first position, referred to as "IG-I", to shut off the engine and electronics. The driver then keys forward to IG-II to start the electronics and continue coasting. The key should remain in the ignition in the IG-II position, and not the IG-I position, in order to avoid engaging the steering wheel lock. The driver recovers normal operation by starting the engine in the normal way, by turning the key to IG-III to crank the starter motor, and then releasing the key back to IG-II. Before putting the transmission in gear, if necessary, the driver may "rev" the engine to match the vehicle's gear and speed. The fuel economy from this advanced technique is increased noticeably over any short distance trip, largely because there are no engine idling losses (see figure below). Most modern automatics' computer systems do a very good job at keeping the transmission in the proper gear while coasting in neutral, and the driver should not be conscious of the tachometer when reengaging, but rather just press half-way down on the accelerator when re-engaging. Some, but not all, hypermilers use this maneuver, and some may use it more safely than others. The technique is used for general coasting, or as part of the pulse-and-glide maneuver, or when going down hills or in other situations when potential energy or momentum will propel the vehicle without engine power. Some hypermilers may use this maneuver while going downhill, around a corner, and without braking; however, that practice is in all likelihood more dangerous than an auto-stop on a level and straight road, where stopping distance is shorter and visibility is greater. Vehicle control may be somewhat compromised, and this can be more or less dangerous or safe depending on the situation. Turning the engine off will cause the power brake assist to be lost after a few applications of the brake pedal. Power steering is instantly lost, although it is not needed at high speed, only at low speed. Steering is still possible at low speed, but can often require considerably more arm strength to turn the wheel. For safety reasons, the maneuver is not recommended for use in traffic, since the driver will want the car to be in gear if sudden acceleration is needed as an evasive maneuver. The driver should first look for traffic behind the vehicle before attempting the maneuver. It can be considered more courteous to not coast if another vehicle is closely following. The proper etiquette and acceptable driving practices are controversial, and is worsened by a lack of communication between drivers. Both sides of the debate are often argued passionately, yet sometimes neither of the proposed driving methods is in complete accordance with the rules of the road. Both hypermilers and regular drivers may at different times violate the same rule yet blame the other type of driver.

Despite the potential risks, it does in fact save fuel to turn the engine off instead of idling. Traffic lights are in most cases predictable, and it is often possible to anticipate when a light will turn green. Some traffic lights (in Europe) have timers on them, which assists the driver in using this tactic. Draft-assisted forced stop, a variation of the forced (auto)stop (sometimes abbreviated as D-FAS), involves turning off the engine and gliding in neutral while drafting a larger vehicle, in order to take advantage of the reduced wind resistance in its immediate wake (This practice is illegal in some areas due to its danger); while tailgating itself is inherently risky, the danger of collision is increased with D-FAS as hydraulic power for power brakes is used up after a few applications of the brake pedal, and there is a loss of hydraulic pressure that provides power steering, however, there is less need for power steering at high speed. Some hybrids must keep the engine running whenever the vehicle is in motion and the transmission engaged, although they still have an "auto-stop" feature which engages when the vehicle stops, avoiding waste. Maximizing use of auto-stop on these vehicles is critical because idling causes a severe drop in instantaneous fuel-mileage efficiency to zero miles per gallon, and this lowers the average (or accumulated) fuel-mileage efficiency. Drafting The US television show Mythbusters (Discovery Channel), in their June 6, 2007, episode, took a series of measurements where they drove a Dodge Magnum Station Wagon at 55 mph (89 km/h) right behind a Freightliner tractor trailer. As they got closer their results ranged from a baseline (no truck) figure of 32 mpg, to 35.5 mpg (11% improvement) at 100 feet (30 m), and then progressively up to 44.5 mpg (a 39% increase) at ten feet, as a result of decreased drag consequent of drafting.

Energy losses

Example energy flows for a late-model midsize passenger car: (a) urban driving; (b) highway driving. Source: U.S. Department of Energy Understanding the distribution of energy losses in a vehicle can help drivers travel more efficiently. Most of the fuel energy loss occurs in the thermodynamic losses of the engine. The second largest loss is from idling, or when the engine is in "standby", which explains the large gains available from shutting off the engine. Very little fuel energy actually reaches the axle. However, any mechanical energy that doesn't go to the axle is energy that doesn't have to be created by the engine, and thus reduces loss in the inefficiency of the engine. In this respect, the data for fuel energy wasted in braking, rolling resistance, and aerodynamic drag are all somewhat misleading, because they do not reflect all the energy

that was wasted up to that point in the process of delivering energy to the wheels. The image reports that on non-highway (urban) driving, 6% of the fuel's energy is dissipated in braking; however, by dividing this figure by the energy that actually reaches the axle (13%), one can find that 46% of the energy reaching the axle goes to the brakes. Also, additional energy can potentially be recovered when going down hills, which may not be reflected in these figures. Any statistic such as this must be based on averages of certain driving behaviors and/or protocols, which are known to vary widely, and these are precisely the behaviors which hypermilers leverage to the full extent possible.

Safety Geoff Sundstrom, director of AAA Public Affairs, notes that "saving fuel and conserving energy are important, but so is safety, and preventing crashes." In the US, optimal highway speed for fuel-efficiency often lies between the legal minimum speed and the legal speed limit, typically 45 to 65 mph (105 km/h). However, these legal speeds may actually be slower than average traffic speed. The hypermiler thus avoids the danger of higher speeds, however, the speed differential created between cars can be problematic in some cases. Driving at speeds much lower than other vehicles may promote other problems; namely, aggressive drivers may choose to tailgate a slower vehicle. Coasting in neutral with or without the engine off may lead to reduced control in some situations, and drafting at any closer than 3 seconds to the vehicle in front is a recognised risk.

Drafting According to the Discovery Channel show Mythbusters, drafting a big rig at close distances is life-threatening and extremely dangerous. They recommended a minimum safe driving distance of at least 150 feet (46 m) from a big rig.

Coasting in neutral Those who warn that coasting can be dangerous claim that the driver has less control of the vehicle, and will take longer to react in an emergency. In a collision-avoidance emergency, the safe technique focuses entirely on controlled braking, and not at all on acceleration. The proper technique is to use threshold braking (maximum deceleration without skidding), then to wait one second for the weight to shift off of the front wheels in order to increase vehicle cornering stability and to increase the maximum lateral acceleration that is possible without skidding, and then to turn the vehicle rather quickly and sharply to avoid the object. If the lead vehicle initiates an emergency stop, the trailing vehicle is likely to need 3 seconds to avoid a collision. While one function of the driving laws is to help increase safety, the attendant safety issues are not always clear cut, and often neither are the laws. Although coasting in neutral is illegal, in some form, in most states in the US, a driver is not legally required to be able to control a vehicle safely when the car is in neutral. Coasting is even advocated in certain circumstances. For example: "If you are on ice and skidding in a straight line,

step on the clutch or shift to neutral." Also, in a stuck throttle emergency, the safe procedure is to put the transmission in neutral, and if that is ineffective, to turn off the engine. In addition, a driver legally needs to have the ability to bring the vehicle to a stop under any circumstances, including when the engine stalls during normal driving. In the event that there is a loss of engine power, decelerating to a stop is recommended as the safest action. As a safety feature, vehicles are designed to retain some limited ability to steer and brake even when all engine power is lost.

Chapter- 4

Fuel Efficiency Boosting Technologies

Piston

Components of a typical, four stroke cycle, DOHC piston engine. (E) Exhaust camshaft, (I) Intake camshaft, (S) Spark plug, (V) Valves, (P) Piston, (R) Connecting rod, (C) Crankshaft, (W) Water jacket for coolant flow.

A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder wall. In popular usage, a complete cylinder assembly, such as an hydraulic cylinder on power excavators and shovels, is incorrectly called a "piston". Such magazines as Popular Science have published articles with this error. Is is possible that the popularity of a Detroit sports team has been a contributing factor.

Piston engines Internal combustion engines There are two ways that an internal combustion piston engine can transform combustion into motive power: the two-stroke cycle and the four-stroke cycle. A single-cylinder twostroke engine produces power every crankshaft revolution, while a single-cylinder fourstroke engine produces power once every two revolutions. Older designs of small twostroke engines produced more pollution than four-stroke engines. However, modern twostroke designs, like the Vespa ET2 Injection utilise fuel-injection and are as clean as fourstrokes. Large diesel two-stroke engines, as used in ships and locomotives, have always used fuel-injection and produce low emissions. One of the biggest internal combustion engines in the world, the Wärtsilä-Sulzer RTA96-C is a two-stroke; it is bigger than most two-storey houses, has pistons nearly 1 metre in diameter and is one of the most efficient mobile engines in existence. In theory, a four-stroke engine has to be larger than a twostroke engine to produce an equivalent amount of power. Two-stroke engines are becoming less common in developed countries these days, mainly due to manufacturer reluctance to invest in reducing two-stroke emissions. Traditionally, two-stroke engines were reputed to need more maintenance (despite exceptions like the Ricardo Dolphin engine, and the Twingle engines of the Trojan car and the Puch 250 motorcycle). Even though the simplest two-stroke engines have fewer moving parts, they could wear out faster than four-stroke engines. However fuel-injected two-strokes achieve better engine lubrication, also cooling and reliability should improve considerably

A piston and its connecting rod.

CAD drawing of crankshaft and pistons.

Large pistons (over 0.5 m incl. connecting rod).

Simplified piston

Two-stroke engine with a tuned expansion pipe

Steam engines Steam engines are usually double-acting (i.e. steam pressure acts alternately on each side of the piston) and the admission and release of steam is controlled by slide valves, piston valves or poppet valves. Steam engines pistons are nearly always comparatively thin discs, essentially; their diameter is several times their thickness. (One exception is the trunk piston, shaped more liku that of a modern internal-combustion engine.)

Pumps Piston pumps can be used to move liquids or compress gases.

Air cannons There are two special type of pistons used in air cannons: close tolerance pistons and double pistons. While in close tolerance pistons, O-rings serve as a valve, O-rings are not used in in double piston types. Close-tolerance pistons have a number of disadvantages: They can swell and stick, their properties alter due to atmospheric changes, and they fit tightly in the cylinder with close tolerances. Backlash may suck some of the bin material into the valve which can cause the piston to stick. Common features of double piston construction: They cannot swell and stick, they fit loosely in the cylinder (no tight tolerances), atmospheric changes do not affect them, and foreign material entering the cylinder doesn't cause sticking.

Drawbacks Since the piston is the main reciprocating part of an engine, its movement creates an imbalance. This imbalance generally manifests itself as a vibration, which causes the engine to be perceivably harsh. The friction between the walls of the cylinder and the piston rings eventually results in wear, reducing the effective life of the mechanism.

The sound generated by a reciprocating engine can be intolerable and as a result, many reciprocating engines rely on heavy noise suppression equipment to diminish droning and loudness. To transmit the energy of the piston to the crank, the piston is connected to a connecting rod which is in turn connected to the crank. Because the linear movement of the piston must be converted to a rotational movement of the crank, mechanical loss is experienced as a consequence. Overall, this leads to a decrease in the overall efficiency of the combustion process. The motion of the crank shaft is not smooth, since energy supplied by the piston is not continuous and it is impulsive in nature. To address this, manufacturers fit heavy flywheels which supply constant inertia to the crank. Balance shafts are also fitted to some engines, and diminish the instability generated by the pistons movement. To supply the fuel and remove the exhaust fumes from the cylinder there is a need for valves and camshafts. During opening and closing of the valves, mechanical noise and vibrations may be encountered. A two-stroke engine does not require valves, meaning it doesn't need a camshaft, making these engines faster and more powerful.

Crankshaft

Crankshaft (red), pistons (gray) in their cylinders (blue), and flywheel (black)

The crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into rotation, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach. It typically connects to a flywheel, to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional or vibrational damper at the opposite end, to reduce the torsion vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal.

History Classical Antiquity

Roman Hierapolis sawmill from the 3rd century AD, the earliest known machine to combine a crank with a connecting rod. The earliest evidence for the crank as part of a machine, that is in combination with a connecting rod, anywhere in the world appears in the late Roman Hierapolis sawmill from the 3rd century AD and two Roman stone sawmills at Gerasa, Roman Syria, and Ephesus, Asia Minor (both 6th century AD). On the pediment of the Hierapolis mill, a waterwheel fed by a mill race is shown powering via a gear train two frame saws which cut rectangular blocks by the way of some kind of connecting rods and, through mechanical necessity, cranks. The accompanying inscription is in Greek.

The crank and connecting rod mechanisms of the other two archaeologically attested sawmills worked without a gear train. In ancient literature, we find a reference to the workings of water-powered marble saws close to Trier, now Germany, by the late 4th century poet Ausonius; about the same time, these mill types seem also to be indicated by the Christian saint Gregory of Nyssa from Anatolia, demonstrating a diversified use of water-power in many parts of the Roman Empire. The three finds push back the date of the invention of the crank and connecting rod back by a full millennium; for the first time, all essential components of the much later steam engine were assembled by one technological culture: With the crank and connecting rod system, all elements for constructing a steam engine (invented in 1712) — Hero's aeolipile (generating steam power), the cylinder and piston (in metal force pumps), non-return valves (in water pumps), gearing (in water mills and clocks) — were known in Roman times.

Middle Ages

Al-Jazari's hand-washing automaton with flush mechanism In the 9th century, the non-manual crank appears in several of the hydraulic machines described by the Banu Musa brothers in their Book of Ingenious Devices. Two of them contain an action which approximates to that of a crankshaft and only a small modification would have required to convert it to a crankshaft. In reality, however, these devices made only partial rotations and could only be lightly loaded, while the historian of technology Lynn White did not classify them even as the simplest application of a crank. The first known use of a crankshaft in a chain pump was in one of Al-Jazari's (1136– 1206) saqiya machines. The concept of minimizing intermittent working is also first

implied in one of al-Jazari's saqiya chain pumps, which was for the purpose of maximising the efficiency of the saqiya chain pump Al-Jazari also constructed a waterraising saqiya chain pump which was run by hydropower rather than manual labour, though the Chinese were also using hydropower for chain pumps prior to him. Saqiya machines like the ones he described have been supplying water in Damascus since the 13th century up until modern times, and were in everyday use throughout the medieval Islamic world. Al-Jazari described a crank and connecting rod system in a rotating machine in two of his water-raising machines. His twin-cylinder pump incorporated a crankshaft, but the device was unnecessarily complex indicating that he still did not fully understand the concept of power conversion. Citing the Byzantine siphon used for discharging Greek fire as an inspiration, Al-Jazari went on to describe the first suction pipes, suction pump, double-action pump, and made early uses of valves and a crankshaft-connecting rod mechanism, when he invented a twin-cylinder reciprocating piston suction pump. This pump is driven by a water wheel, which drives, through a system of gears, an oscillating slot-rod to which the rods of two pistons are attached. The pistons work in horizontally opposed cylinders, each provided with valve-operated suction and delivery pipes. The delivery pipes are joined above the centre of the machine to form a single outlet into the irrigation system. This water-raising machine had a direct significance for the development of modern engineering. This pump is remarkable for three reasons: • • •

The first known use of a true suction pipe (which sucks fluids into a partial vacuum) in a pump. The first application of the double-acting principle. The conversion of rotary to reciprocating motion, via the crank-connecting rod mechanism.

Al-Jazari's suction piston pump could lift 13.6 m (45 ft) of water, with the help of delivery pipes. This was more advanced than the suction pumps that appeared in 15thcentury Europe, which lacked delivery pipes. It was not, however, any more efficient than a noria commonly used by the Muslim world at the time.

Vigevano's war carriage The Italian physician Guido da Vigevano (c. 1280−1349), planning for a new crusade, made illustrations for a paddle boat and war carriages that were propelled by manually turned compound cranks and gear wheels (center of image). The Luttrell Psalter, dating to around 1340, describes a grindstone which was rotated by two cranks, one at each end of its axle; the geared hand-mill, operated either with one or two cranks, appeared later in the 15th century; Taqi al-Din incorporated a crankshaft in a six-cylinder pump in 1551.

In China, the potential of the crank of converting circular motion into reciprocal one never seems to have been fully realized, and the crank was typically absent from such machines until the turn of the 20th century.

Renaissance

15th century paddle-wheel boat whose paddles are turned by single-throw crankshafts (Anonymous of the Hussite Wars) The first depictions of the compound crank in the carpenter's brace appear between 1420 and 1430 in various northern European artwork. The rapid adoption of the compound crank can be traced in the works of the Anonymous of the Hussite Wars, an unknown German engineer writing on the state of the military technology of his day: first, the connecting-rod, applied to cranks, reappeared, second, double compound cranks also began to be equipped with connecting-rods and third, the flywheel was employed for these cranks to get them over the 'dead-spot'. In Renaissance Italy, the earliest evidence of a compound crank and connecting-rod is found in the sketch books of Taccola, but the device is still mechanically misunderstood. A sound grasp of the crank motion involved demonstrates a little later Pisanello who painted a piston-pump driven by a water-wheel and operated by two simple cranks and two connecting-rods.

Water-raising pump powered by crank and connecting rod mechanism (Georg Andreas Böckler, 1661) One of the drawings of the Anonymous of the Hussite Wars shows a boat with a pair of paddle-wheels at each end turned by men operating compound cranks (see above). The concept was much improved by the Italian Roberto Valturio in 1463, who devised a boat with five sets, where the parallel cranks are all joined to a single power source by one connecting-rod, an idea also taken up by his compatriot Francesco di Giorgio. Crankshafts were also described by Konrad Kyeser (d. 1405), Leonardo da Vinci (1452– 1519) and a Dutch "farmer" by the name Cornelis Corneliszoon van Uitgeest in 1592. His wind-powered sawmill used a crankshaft to convert a windmill's circular motion into a

back-and-forward motion powering the saw. Corneliszoon was granted a patent for his crankshaft in 1597. From the 16th century onwards, evidence of cranks and connecting rods integrated into machine design becomes abundant in the technological treatises of the period: Agostino Ramelli's The Diverse and Artifactitious Machines of 1588 alone depicts eighteen examples, a number which rises in the Theatrum Machinarum Novum by Georg Andreas Böckler to 45 different machines, one third of the total.

Design

Components of a typical, four stroke cycle, DOHC piston engine. (E) Exhaust camshaft, (I) Intake camshaft, (S) Spark plug, (V) Valves, (P) Piston, (R) Connecting rod, (C) Crankshaft, (W) Water jacket for coolant flow. Large engines are usually multicylinder to reduce pulsations from individual firing strokes, with more than one piston attached to a complex crankshaft. Many small engines, such as those found in mopeds or garden machinery, are single cylinder and use only a single piston, simplifying crankshaft design. This engine can also be built with no riveted seam.

Bearings The crankshaft has a linear axis about which it rotates, typically with several bearing journals riding on replaceable bearings (the main bearings) held in the engine block. As the crankshaft undergoes a great deal of sideways load from each cylinder in a multicylinder engine, it must be supported by several such bearings, not just one at each end. This was a factor in the rise of V8 engines, with their shorter crankshafts, in preference to straight-8 engines. The long crankshafts of the latter suffered from an unacceptable amount of flex when engine designers began using higher compression ratios and higher rotational speeds. High performance engines often have more main bearings than their lower performance cousins for this reason.

Piston stroke The distance the axis of the crank throws from the axis of the crankshaft determines the piston stroke measurement, and thus engine displacement. A common way to increase the low-speed torque of an engine is to increase the stroke, sometimes known as "shaftstroking." This also increases the reciprocating vibration, however, limiting the high speed capability of the engine. In compensation, it improves the low speed operation of the engine, as the longer intake stroke through smaller valve(s) results in greater turbulence and mixing of the intake charge. For this reason, even such high speed production engines as current Honda engines are classified as "under square" or longstroke, in that the stroke is longer than the diameter of the cylinder bore. As such, finding the proper balance between shaft-stroking speed and length will lead to more optimal results.

Engine configuration The configuration and number of pistons in relation to each other and the crank leads to straight, V or flat engines. The same basic engine block can be used with different crankshafts, however, to alter the firing order; for instance, the 90° V6 engine configuration, in older days sometimes derived by using six cylinders of a V8 engine with what is basically a shortened version of the V8 crankshaft, produces an engine with an inherent pulsation in the power flow due to the "missing" two cylinders. The same engine, however, can be made to provide evenly spaced power pulses by using a crankshaft with an individual crank throw for each cylinder, spaced so that the pistons are

actually phased 120° apart, as in the GM 3800 engine. While production V8 engines use four crank throws spaced 90° apart, high-performance V8 engines often use a "flat" crankshaft with throws spaced 180° apart. The difference can be heard as the flat-plane crankshafts result in the engine having a smoother, higher-pitched sound than cross-plane (for example, IRL IndyCar Series compared to NASCAR Nextel Cup, or a Ferrari 355 compared to a Chevrolet Corvette).

Engine balance For some engines it is necessary to provide counterweights for the reciprocating mass of each piston and connecting rod to improve engine balance. These are typically cast as part of the crankshaft but, occasionally, are bolt-on pieces. While counter weights add a considerable amount of weight to the crankshaft, it provides a smoother running engine and allows higher RPMs to be reached.

Rotary engines Many early aircraft engines (and a few in other applications) had the crankshaft fixed to the airframe and instead the cylinders rotated, known as a rotary engine design. Rotary engines such as the Wankel engine are referred to as pistonless rotary engines. In the Wankel engine, also called a rotary engine, the rotors drive the eccentric shaft, which could be considered the equivalent of the crankshaft in a piston engine.

Construction

Continental engine marine crankshafts, 1942 Crankshafts can be monolithic (made in a single piece) or assembled from several pieces. Monolithic crankshafts are most common, but some smaller and larger engines use assembled crankshafts.

Forging and casting Crankshafts can be forged from a steel bar usually through roll forging or cast in ductile steel. Today more and more manufacturers tend to favor the use of forged crankshafts due to their lighter weight, more compact dimensions and better inherent dampening. With forged crankshafts, vanadium microalloyed steels are mostly used as these steels can be air cooled after reaching high strengths without additional heat treatment, with exception to the surface hardening of the bearing surfaces. The low alloy content also makes the material cheaper than high alloy steels. Carbon steels are also used, but these require additional heat treatment to reach the desired properties. Iron crankshafts are today mostly found in cheaper production engines (such as those found in the Ford Focus diesel engines) where the loads are lower. Some engines also use cast iron crankshafts for low output versions while the more expensive high output version use forged steel.

Machining

Crankshafts can also be machined out of a billet, often using a bar of high quality vacuum remelted steel. Even though the fiber flow (local inhomogeneities of the material's chemical composition generated during casting) doesn’t follow the shape of the crankshaft (which is undesirable), this is usually not a problem since higher quality steels which normally are difficult to forge can be used. These crankshafts tend to be very expensive due to the large amount of material removal which needs to be done by using lathes and milling machines, the high material cost and the additional heat treatment required. However, since no expensive tooling is required, this production method allows small production runs of crankshafts to be made without high costs.

Fatigue strength The fatigue strength of crankshafts is usually increased by using a radius at the ends of each main and crankpin bearing. The radius itself reduces the stress in these critical areas, but since the radii in most cases are rolled, this also leaves some compressive residual stress in the surface which prevents cracks from forming.

Hardening Most production crankshafts use induction hardened bearing surfaces since that method gives good results with low costs. It also allows the crankshaft to be reground without having to redo the hardening. But high performance crankshafts, billet crankshafts in particular, tend to use nitridization instead. Nitridization is slower and thereby more costly, and in addition it puts certain demands on the alloying metals in the steel, in order to be able to create stable nitrides. The advantage with nitridization is that it can be done at low temperatures, it produces a very hard surface and the process will leave some compressive residual stress in the surface which is good for the fatigue properties of the crankshaft. The low temperature during treatment is advantageous in that it doesn’t have any negative effects on the steel, such as annealing. With crankshafts that operate on roller bearings, the use of carburization tends to be favored due to the high Hertzian contact stresses in such an application. Like nitriding, carburization also leaves some compressive residual stresses in the surface.

Counterweights Some expensive, high performance crankshafts also use heavy-metal counterweights to make the crankshaft more compact. The heavy-metal used is most often a tungsten alloy but depleted uranium has also been used. A cheaper option is to use lead, but compared with tungsten its density is much lower.

Stress on crankshafts The shaft is subjected to various forces but generally needs to be analysed in two positions. Firstly, failure may occur at the position of maximum bending; this may be at the centre of the crank or at either end. In such a condition the failure is due to bending

and the pressure in the cylinder is maximal. Second, the crank may fail due to twisting, so the conrod needs to be checked for shear at the position of maximal twisting. The pressure at this position is the maximal pressure, but only a fraction of maximal pressure.

Alloy wheel

Alloy wheel on a passenger car Alloy wheels (also known as rims) are automobile (car, motorcycle and truck) wheels which are made from an alloy of aluminium or magnesium (or sometimes a mixture of both). They are typically lighter for the same strength and provide better heat conduction and improved cosmetic appearance.

Characteristics

Alcoa's heavy-duty alloy wheel, for buses and trucks. Lighter wheels can improve handling by reducing unsprung mass, allowing suspension to follow the terrain more closely and thus improve grip, however not all alloy wheels are lighter than their steel equivalents. Reduction in overall vehicle mass can also help to reduce fuel consumption. Better heat conduction can help dissipate heat from the brakes, which improves braking performance in more demanding driving conditions and reduces the chance of brake failure due to overheating.

An aluminium alloy wheel Alloy wheels are also purchased for cosmetic purposes although the alloys used are not corrosion-resistant. Alloys allow the use of attractive bare-metal finishes, but these require to be sealed with paint or wheel covers. Even if so protected the wheels in use will eventually start to corrode after 3 to 5 years but refurbishment is now widely available at a cost. The manufacturing processes also allow intricate, bold designs. In contrast, steel wheels are usually pressed from sheet metal, and then welded together (often leaving unsightly bumps) and must be painted to avoid corrosion and/or hidden with wheel covers / hub caps. Alloy wheels are prone to galvanic corrosion if appropriate preventive measures are not taken, which can in turn cause the tires to leak air. Also, alloy wheels are more difficult to repair than steel wheels when bent, but their higher price usually makes repairs cheaper than replacement and even severely damaged wheels can often be repaired to like new using a 10 point process , though this depends on how badly the owner wishes to salvage the wheel and its intrinsic worth or availability.

Chrysler alloy wheel Alloy wheels are more expensive to produce than standard steel wheels, and thus are often not included as standard equipment, instead being marketed as optional add-ons or as part of a more expensive trim package. However, alloy wheels have become considerably more common since 2000, now being offered on economy and subcompact cars, compared to a decade earlier where alloy wheels were often not factory options on inexpensive vehicles. Alloy wheels have long been included as standard equipment on higher-priced luxury or sports cars, with larger-sized or "exclusive" alloy wheels being options. The high cost of alloy wheels makes them attractive to thieves; to counter this, automakers and dealers often use locking wheel nuts which require a special key to remove. Most alloy wheels are manufactured using casting, but some are forged. Forged wheels are usually lighter, stronger, but much more expensive than cast wheels.

Aftermarket wheels A sizeable selection of alloy wheels (sometimes called "mags"—see below) are available to automobile owners who want lighter, more visually appealing, rarer, and/or larger wheels on their cars. Many people may think that large wheels automatically result in increased performance, handling and suspension, yet Car and Driver performed a test of

different sized wheels from 15" to 19" all outfitted with the same make and model of tires and showed that both 0-60 times and fuel economy were reduced with larger wheels. They also noted that ride comfort and noise were negatively affected by the larger wheels. The larger aftermarket wheels and the corresponding tires have considerably higher cost and weight, for little benefit in return. The aura of larger wheels apparently is that they seem to signify luxury, sportiness, or wealth. These wheels have become a part of pop culture (as with "dubs").

Aftermarket brands The many aftermarket wheel brands include PDW Wheels, TSW Alloy Wheels, BMF Wheels, Eurotech Wheels, Zforce, Akuza, Incubus, Viscera, Cattivo, Ballistic, Menzari, Devino, Eta Beta Wheels, Antera, Marchesini, Sparco, Speedline, TeamDynamics, NAD Wheels, R2 Wheels, Lowenhart, Rial, Orobica Line, M.B Italia, Kormetal, Toora, G.M.P Italia, Vellano, MOZ, Watanabe, SSR Wheels, Wolfhart, Wolfrace, Panther Wheel, American Racing Wheels, UsaRim, Motegi Racing Performance Wheels, Weld Racing, BBS Wheels, CMS, 5Zigen, Volk Racing, Konig Wheels and Rimstock. Most aftermarket wheels are cast, while only a few above are forged, such as Vellano, and Weld. Many companies have been formed over the years (some recently) due to the increasing demand from street racing enthusiasts and the rising demand for larger diameter wheels. MHT wheel markets a brand under the name DUB that offers a Spinner wheel, the center of the wheel continues spinning after the vehicle comes to a stop, and the Floater, the center of the wheel stays stationary during movement giving the look that the vehicle isn't moving. Cast aftermarket wheels have also been oversaturated due to the vast influx of inexpensive chrome wheels from China. India, through Synergies Castings Ltd. and other companies, of late have also emerged as a major supplier of alloy/chrome wheels. They manufacture products to global scale due to primarily cheap but highly skilled and qualified labour. American Racing, which owns Motegi Racing and Weld Racing among other brands such as TIS, TIS Modular, is the oldest aftermarket wheel company dating back to 1956. The oldest British company is Wolfrace who was the first company to offer a polished alloy wheel in Europe and to achieve TUV approval. Wolfrace also provided the wheels for thrust SSC and the UK's land speed record bid. A recent trend in the industry includes joint venture partnerships being formed between offshore manufacturers and local importers/distributors such as PDW Wheels which started in Australia in 2006, amongst a few others. Most wheel brands are ultimately sold through dealers such as RhinoTuning. Some "aftermarket" are/were also available as Original equipment manufacturer (OEM) fitments, with BBS being a notable original equipment supplier to Volkswagen. Some manufacturers also share patterns and castings, with an example (motorcycle) being the licencing of Marchesini 5-spoke design to Brembo, for the production of alloy (non-magnesium) wheels for Ducati road bikes.

Magnesium alloy wheels

Magnesium alloy wheel on a Porsche Carrera GT Magnesium alloy wheels, or "mag wheels", are sometimes used on racing cars, in place of heavier steel or aluminium wheels, for better performance. The wheels are produced by one-step hot forging from a magnesium alloy known as ZK60, AZ31 or AZ91 (MA14 in Russia). Cast magnesium disks are used in motorcycle wheels. The mass of a typical magnesium automotive wheel is about 5–9 kg (depending on size). Magnesium wheels are flammable and have been banned in some forms of motorsport in the UK following fires which are very difficult to extinguish. Mag wheels have been known to catch fire in competition use after a punctured tire has allowed prolonged scraping of the wheel on the road surface. Some variants of magnesium alloy wheels may have low corrosion resistance. They have the disadvantages of being expensive and not practical for most road vehicles. Aluminium wheels are often mistakenly called "mag wheels".

Chapter- 5

Specimens for Transport Fuel Efficiency

Honda Insight

The Honda Insight is a hybrid electric vehicle manufactured by Honda and the first production vehicle to feature Honda's Integrated Motor Assist system. The firstgeneration Insight was produced from 1999 to 2006 as a three-door hatchback. Honda introduced the second-generation Insight to its home market of Japan in February 2009. The car went on sale in the United States on March 24, 2009. At $19,800 as a fivedoor hatchback it is the least expensive hybrid available in the US. In December 2010, Honda introduced a less expensive base model for the 2011 model year priced US$18,200. The Insight was launched April 2009 in the U.K as the most affordable hybrid on the market with a starting price from £15,490 (otr), which was more than

£2,000 lower than other hybrids, and became the best selling hybrid. Honda's Insight, billed as the cheapest gas-electric hybrid on the market, ranked as the top-selling vehicle in Japan for April 2009, the first time a hybrid has clinched that spot. During its first twelve months after first available in the Japanese market, the second-generation Insight sold 143,015 units around the world.

First generation (2000–2006)

History Based on the Honda J-VX concept car unveiled at the 1997 Tokyo Motor Show, the Insight was first introduced in Japan in November 1999 and was the first production vehicle to feature Honda's Integrated Motor Assist system. In the following month, December 1999, Insight became the first hybrid available in North America, beating Toyota's Prius by seven months. It featured optimized aerodynamics and a lightweight aluminum structure to maximize fuel efficiency and minimize emissions.

Design

Honda Insight rear

A 1953 Jaguar XK120 coupé with steel wheels and spats The Honda Insight was a subcompact hatchback 3,945 mm (155.3 in) in length with a wheelbase of 2,400 mm (94.5 in) a height of 1,355 mm (53.3 in) and a width of 1,695 mm (66.7 in). The Insight was only available as a two-seater. Only three different

trims were available: a manual transmission without air-conditioning, a manual transmission with automatic climate-control system, and a continuously variable transmission (CVT) with automatic climate-control system. Although produced until 2006, the only major change was the introduction of a trunk mounted, front controlled, multiple CD changer. Nearly all practical means were used to reduce fuel consumption while meeting modern requirements. In addition to the hybrid drive system, it was small, built of light materials and streamlined. The New York Times wrote that the Insight's styling "suggested Popeye's pal, Olive Oyl, in her ankle-length dress. The rear fender skirts seemed frumpy." However, wheel skirts have not always been considered frumpy.

Technology

Honda Insight IMA The gasoline engine is a 67 hp (50 kW; 68 PS), 1-liter, ECA series 3-cylinder unit providing lean burn operation with an air-to-fuel ratio that can reach 25.8 to 1. The electrical motor assist adds another 10 kW (13 hp) and a maximum of 36 pound-feet (49 Nm) of torque when called on. It also acts as a generator during deceleration and braking to recharge the vehicle's batteries, and as the Insight's starter motor. (This both improves fuel efficiency and also extends the lifetime and fade resistance of the brakes, without adding unsprung weight). When the car is not moving, for example, at a stop light, the engine shuts off. The digital displays on the dashboard display fuel consumption instantaneously. On the manual transmission up and down arrows suggest when to shift gears. The Insight uses the first generation of Honda's Integrated Motor Assist (IMA) hybrid technology. (The next generation, used in the Honda Civic Hybrid, is much more

space-efficient.) The Insight has a 3-cylinder 1.0 L (61 cu in) engine and an ultrathin (about 2.5 inches) brushless 10-kW electric motor located on the crankshaft. The engine utilizes lightweight aluminum, magnesium, and plastic to minimize weight. Located behind the seats are a series of commercial grade "D" sized NiMH batteries wired to provide a nominal 144 V DC. During heavy acceleration, up to 100 amps are pulled from the NiMH batteries as the electric motor provides additional power; during deceleration, the motor acts as a generator and recharges the batteries using a process called regenerative braking, charging them with up to 50 Amps of current. A computer control module regulates how much power comes from the internal combustion engine, and how much from the electric motor; in the CVT variant, it also finds the optimal gear ratio. Dashboard gauges monitor the current battery status, instantaneous fuel consumption, and mode of the electric motor — standby, engine assist or charging the batteries. High pressure, low rolling resistance tires and the use of low viscosity "0W-20" synthetic oil both enhance fuel economy. The original Insight had a conventional manual transmission. Starting with the 2001 model, a CVT variant of the Insight was available; the CVT is similar to that used in the Honda Civic Hybrid and the Honda Logo. A traditional transmission shifts between a fixed set of engine-to-wheel ratios; however, a CVT allows for an infinite set of ratios between its lowest gear and its highest. A feature shared by the two hybrids (and now appearing in others) is the ability to automatically turn off the engine when the vehicle is at a stop (and restart it upon movement). Since it is more powerful than most starters of conventional cars, the Insight's electric motor can start the engine nearly instantaneously. The Integrated Motor Assist is run by an "Intelligent Power Unit (IPU)", a desktop computer-sized box. The Intelligent Power Unit, the Power control Unit, the Electronic Control Unit, the vehicle's batteries, converter and a high-voltage inverter are all located under the cargo floor of the vehicle, behind the seats. One key in increasing the vehicle's fuel efficiency was reducing the mass via the extensive use of aluminum and plastic. Not only is the body aluminum, like those of some traditional specialized cars, but it has an aluminum unit body/frame structure with extruded members like the NSX. Honda built the Insight with aluminum front brake calipers and rear brake drums, and with a largely aluminum suspension, in addition to standard aluminum wheels; all these reduced the ratio of un-sprung to sprung weight as well as the total weight. (This may have been needed to compensate for the bouncy ride of the high pressure low friction tires.) The fuel tank was plastic; the engine mounts were aluminum; and the exhaust was a small, thin wall pipe. Even the compact spare is aluminum. The Insight weighed 1,847 lb (838 kg) in manual transmission form or 1,964 lb (891 kg) with CVT and air conditioning. The combination of materials and design gave the Insight body structure 13 percent more bending strength and 38 percent more torsional rigidity than a comparably-sized steel body, despite weighing 40 percent less. To maximize fuel efficiency and give good high speed performance with its small engine, the Insight is very aerodynamic. It has a coefficient of drag of 0.25, one of the lowest of any marketed automobile. Because it has no rear seat, the body can start tapering

narrower and lower just behind the driver's head, approximating the classic tear drop more closely than is possible in a four passenger car. The rear fenders limit the taper of the lower part, but the rear track is narrower than the front track. The CVT-equipped Insight was classified as a super-low emissions vehicle. The Insight features low emissions: the California Air Resources Board gave the 5-speed model a ULEV rating, and the CVT model earned a SULEV rating – 5-speed model charismatic lean-burn ability was a trade-off for increased efficiency at the expense of slightly higher NOx emissions.

Manufacturing The Insight was assembled at the Honda factory in Suzuka, Japan, where the Honda NSX and the Honda S2000 were also assembled. The Insight and the NSX are aluminumbodied, while the S2000 employs a steel body. At the 2003 Tokyo Motor Show, Honda introduced the concept car Honda IMAS, an extremely fuel-efficient and lightweight hybrid car made of aluminum and carbon fiber, which was perceived by most observers to be the future direction where the Insight is heading. Having aluminum body and frame, Insight was an expensive car to produce and was never designed for high-volume sales. Instead it was designed to be a real world test car for hybrid technology and a gauge to new consumer driving habits. With an aerodynamic fuel-saving shape similar to Audi A2, and some unconventional body colors it was a bit more than mainstream car buyers could handle, preferring more conservative styles. Production halt was announced in May 2006, along with plans to replace Insight with a new hybrid car, smaller than the eighth generation Civic, but not earlier than in 2009. Ahead of this announcement, Honda stopped selling Insight in the UK, for example, as early as December 2005. To fill in the market niche void, in 2002 Honda rolled out a hybrid version of the Honda Civic – Honda Civic Hybrid, followed by Toyota's relaunch of the Prius in 2003.

Sales Total global sales for the first generation Insight were 17,020 units.

US market The Insight was the first mass-produced hybrid automobile sold in the United States, achieving 70 miles per US gallon (3.4 L/100 km; 84 mpg-imp) per its then current United States Environmental Protection Agency (EPA) highway rating. Insight was introduced in US at a base price of just US$18,880. Other hybrids soon followed, with the Toyota Prius arriving in June 2000.

Fuel efficiency The car remained the most fuel efficient machine available in the U.S. while it was produced and is still the leader of any current mass market car. The Insight earned an EPA fuel efficiency estimate of 70 miles per US gallon (3.4 L/100 km; 84 mpg-imp) in highway driving, 61 mpg-US (3.9 L/100 km; 73 mpg-imp) city. With air conditioning it was 66 mpg-US (3.6 L/100 km; 79 mpg-imp)/60 mpg-US (3.9 L/100 km; 72 mpg-imp). With a CVT it was 57 mpg-US (4.1 L/100 km; 68 mpg-imp)/56 mpg-US (4.2 L/100 km; 67 mpg-imp). Insight aficionados who are "hypermilers" compete to eke out as many miles as possible from a tank. Upon the Insight's release, Honda challenged several automotive magazines to a competition to see who could obtain the best fuel efficiency on the 195-mile (314 km) drive from Columbus, Ohio to Detroit. The contest was won by Car and Driver magazine, which rigged a box behind a Ford Excursion, and had the Insight drive within the confines of the box. With much less wind resistance, the Insight made the trip with a fuel consumption of 121.7 miles per US gallon (1.933 L/100 km; 146.2 mpg-imp), while averaging 58 miles per hour (93 km/h). A two-year test of an Insight with air conditioning, driven 40,000 miles (64,000 km), averaged 48 miles per US gallon (4.9 L/100 km; 58 mpg-imp).

Usage incentives Under the Energy Policy Act of 2005 in the United States, the Honda Insight was eligible for a US$1,450 tax credit. In California, the state with the most-stringent fuel economy standards, the manualtransmission Insight was rated as an ultra-low-emission vehicle and the CVT transmission was rated Super-ultra-low-emission vehicle. Cars registered in the UK after 2001 qualified for free road tax because of their low CO2 emissions (2000 registered cars would be taxed on the lower rate of the old system based on engine size). As a Hybrid the Insight also qualifies for an exemption from the London Congestion Charge.

Replacement battery pack As of June 2008 in the U.S., according to Honda, there are fewer than 200 battery failures beyond warranty coverage out of more than 100,000 hybrids sold. Honda has extended the US warranties on the hybrid battery pack and controlling computers from the original 8 years or 80,000 miles (130,000 km) to 10 years from the in-service date or 150,000 miles (240,000 km). In addition, as of May 2008, as part of a class-action suit settlement, Honda had extended the warranty of the batteries on 2002– 2006 cars to 157,500 miles (253,500 km). On June 1, 2008, Honda dropped the cost of replacement battery for Insight from US$3,400 to US$1,968. There is an additional

installation charge by dealers of around US$900 at that time. As of February 2010, out of warranty battery replacement for 2000-2006 Honda Insights requires updates to the BCM (battery charge computer) and the MCM (electric motor control computer) unless they have the current versions. The MCM can be reprogrammed in 2002–2006 cars, but must be replaced on 2000–2001 cars. The BCM is not reprogrammable and must be replaced. This increases the cost of the battery replacement by approximately US$800 for 2002– 2006 vehicles and US$1700 for 2000–2001 Insights. Reported price quotes from dealers range from a low of US$3600 (2002–2006) or US$4500 (2000–2001) to a high of US$5900. As of 2008, independent mechanics have been known to replace Insight batteries with either Prius sub-packs or Civic Hybrid subpacks. 2003–2005 Civic Hybrid subpacks are direct replacements for 2000–2006 Insight subpacks. A US$400 used NiMH battery from another more mass produced HEV (2003–2005 Honda Civic Hybrid) can be used to build a replacement Insight battery pack. Other independent mechanics have been reconditioning their old Insight battery packs to correct wear and tear issues. Reconditioning allows correction of some issues at lower cost than rebuilding a replacement pack from other used packs.

Recalls On July 26, 2002 Honda recalled 375 2002 Insights due to improperly welded air bag modules.

Second generation (2010–)

Honda Insight Concept In 2009, Honda introduced its second-generation Insight based on an all-new, 5passenger, 5-door, dedicated hybrid platform, which was also later used for the Honda CR-Z. The concept version of the Insight hatchback hybrid electric vehicle had made its public debut at the 2008 Paris Motor Show. and its North American debut at the Los Angeles Auto Show. In the US, the new Insight is classified as a compact car based on its interior volume.

Honda Insight interior

Fuel efficiency Estimated fuel efficiency according to the U.S. EPA testing methodology is: City 40 mpgUS (5.9 L/100 km; 48 mpg-imp), Highway 43 mpg-US (5.5 L/100 km; 52 mpg-imp), Combined 41 mpg-US (5.7 L/100 km; 49 mpg-imp). Honda UK state that the official UK fuel efficiency data for the Insight SE is: Urban 61.4 mpg-imp (4.60 L/100 km; 51.1 mpg-US), Extra urban 67.3 mpg-imp (4.20 L/100 km; 56.0 mpg-US), Combined 64.2 mpg-imp (4.40 L/100 km; 53.5 mpg-US) and the CO2 emissions rating is: 101 g/km, putting it in the second lowest UK road tax band.

Performance Car and Driver magazine performed a comparison between the 2010 Honda Insight and the 2010 Toyota Prius. In this test, the Insight achieved 0–60 mph in 10.3 seconds (Prius, 10.0 seconds), the quarter mile in 17.9 seconds @ 78 mph (Prius, 17.6 @ 79 mph), and 70–0 mph braking in 181 feet (Prius, 182 feet). The Insight's average fuel economy during a 600-mile controlled evaluation was 38 mpg (Prius, 42 mpg). Overall, Car and Driver selected the Insight as their preferred vehicle due to its "fun-to-drive" qualities including superior handling, steering, braking, and paddle-shifted transmission.

History The 2010 Honda Insight was specifically designed to make hybrid technology more affordable to a wide range of buyers. Departing from the first generation Insight’s twoseater configuration, the 2010 Insight is a 5-passenger, 5-door dedicated hybrid vehicle that includes the fifth generation of Honda’s Integrated Motor Assist (IMA) hybrid powertrain.

Design Honda chose a 5-door hatchback configuration for the latest Insight. The wedge-shaped body assists aerodynamics and reduces drag for improved fuel economy. The 5-passenger accommodations enhance marketability and the overall vehicle shape, as Honda puts it, is “clearly identifiable as a hybrid.” The reason we chose a five-door hatchback was that we wanted the car to be popular in Europe. American Honda – the biggest market – asked us to build a car with a boot, but we rejected that idea, because to compete with other green cars and sell more in Europe, it had to be a five-door hatchback. Of course, aerodynamically it is also a more favourable shape. —Yasunari Seki, Honda Insight Project Leader, The Insight's exterior design merges design cues from both the first generation Insight (the tapered tail and triangular taillights) and Honda’s production hydrogen fuel cell vehicle, the FCX Clarity (the low hood, six-point front grille, and wedge-shaped profile). The interior of the new Insight includes a variation of the two-tier instrument panel first introduced on the 2006 Honda Civic. In this arrangement, a digital speedometer is mounted high on the instrument panel within the driver’s normal line-of-site for ease of visibility. An analog tachometer, fuel gauge, hybrid assist gauge, and Multi-Information Display are housed in the lower tier.

Powertrain The new Insight includes Honda’s fifth and latest generation of its Integrated Motor Assist (IMA) hybrid system. This system mates an internal combustion engine with an electric motor mounted directly to the engine’s crankshaft between the engine and transmission. Honda states that this configuration is less complex, lower cost, and compact enough to accommodate a wide range of vehicle sizes when compared to competing hybrid powertrains. Honda has used previous generations of this IMA system on all of its production hybrid vehicles including the original Insight, Civic Hybrid, and Accord Hybrid. Advanced development has allowed the Insight’s IMA system to be 19 percent smaller and 28 percent lighter than the previous generation IMA used in the existing Civic Hybrid.

The Insight’s IMA includes a high-efficiency, lightweight, low-friction 1.3-liter SOHC iVTEC 4-cylinder engine and it is rated for 98 hp (73 kW) at 5800 rpm and 123 lb·ft (167 N·m) of torque from 1000–1700 rpm. The high torque at low rpm is made possible by the electric motor which contributes up to 13 hp (10 kW) at 1500 rpm and 58 lb·ft (79 N·m) of torque at 1000 rpm to the powertrain, assisting in acceleration and some steady state cruising situations at low-to-mid vehicle speeds. The motor acts as a generator during braking, steady cruising, gentle deceleration and coasting in order to recharge the IMA battery. The motor also serves as the engine starter, quickly spinning the engine to idle speed after Idle Stop and during normal vehicle starting. The system will automatically switch to a back-up, conventional 12-volt starter to start the engine if the IMA system is disabled or if the car is started at extreme cold temperatures. As an additional safety feature, Honda’s hybrid configuration allows the car to operate like a conventional, gasengine vehicle even if the IMA hybrid-electric motor system is completely disabled. The Insight’s Continuously Variable Transmission (CVT) provides infinite ratios to keep the engine operating within its most efficient range. Forward gear ratios are infinitely variable between 3.172–0.529 and reverse gear ranges from 4.511~1.693. Final drive is 4.20:1. On Insight EX models, paddle shifters mounted behind the steering wheel allow the driver to engage a manual shift mode and select from seven simulated gear ratios for full control over acceleration and engine braking. Since the CVT’s gear ratios are continuously variable the system electronically directs the transmission to up- or downshift into pre-determined ratios when the driver taps the shift paddles. In normal driving, the CVT allows the engine and IMA motor to stay in their most efficient operating range thereby providing superior fuel efficiency to that of a conventional automatic transmission with fixed gear ratios. The CVT’s variable gear ratios allow for both quick, initial acceleration and efficient, low-rpm cruising. In order to allow the powertrain computer to optimize performance under every driving condition, the Insight’s accelerator pedal is a “drive-by-wire” type that uses an electronic position sensor instead of the conventional metal cable that usually connects the pedal to the engine’s throttle body. In the drive-by-wire system, the engine’s throttle body is controlled by the powertrain computer in response to the gas pedal position—allowing the computer to determine the optimal throttle body, fuel, and CVT settings based on the accelerator pedal position and its rate of travel.

IMA battery The Insight’s IMA is powered by a flat, nickel metal hydride battery pack located below the cargo floor between the rear wheels. The 84 module battery is manufactured by Panasonic and provides a nominal system voltage of 100.8 volts with a nominal capacity of 5.75 ampere-hours. The power density of the modules is 30 percent greater than in the current-generation Civic Hybrid. The battery is recharged automatically by scavenging engine power, when needed, and by regenerative braking when the car is decelerating. The power management electronics, battery modules, and cooling system are all selfcontained within the IMA battery pack.

Honda ECO ASSIST System The new Insight is the first Honda hybrid to feature their Ecological Drive Assist System (ECO ASSIST). This system is designed to help the driver develop and maintain a fuelefficient driving style. The system monitors and displays the positive or negative effect of a driving style on the vehicle’s fuel economy. As a visual aid, the background of the Insight’s digital speedometer glows green when the car is being driven in an efficient manner. Somewhat less-efficient driving makes the meter glow blue-green. Aggressive starts and stops that consume extra fuel make the meter glow blue. By observing the color shift of the speedometer background, the driver receives assistance in developing driving habits that typically enhance fuel economy. In addition, ECO ASSIST includes a dedicated ECON button that enables the driver to initiate a range of functions that increase the fuel economy of the IMA system via a single button press. In ECON mode, the driver trades off a measure of performance for enhanced fuel economy but gains the following advantages: • • • • •

Increases the potential for engaging the Idle Stop feature sooner Operates air conditioning more in recirculation mode Reduces automatic climate control blower fan speed Optimizes throttle angle input and CVT operation Limits power and torque by approximately 4 percent (full responsiveness is provided at wide-open-throttle)

Overall, ECO ASSIST is designed to assist the driver in adopting a balanced approach between efficient highway commuting and efficient city driving. However, the EPA found during fuel economy testing that using the ECO ASSIST mode "registered no effect" on its fuel economy rating. "It relaxes throttle response, so the test driver simply compensates with additional throttle to achieve the required speeds."

Chassis, suspension, and steering The Insight’s compact chassis is derived from components used in the latest Honda Fit. The structure of the engine compartment and front section of the chassis is almost identical to the Fit’s but with additional enhancements to aid crash protection. From the firewall aft the platform is unique to Insight. The most significant difference between the Fit and the Insight platform is the position of the fuel tank. Whereas the Fit locates the fuel tank under the front seats (a move designed to free up space for maximum versatility in the Fit’s rear compartment) the Insight positions the fuel tank under the rear seats. This fuel tank location enables the Insight’s hybrid battery pack to be located in the cargo floor below the spare tire, a move that allows folding rear seats, a lower roofline, and a more aerodynamic body shape to assist fuel economy at high speed.

Front and rear suspension components from the Fit are used including MacPherson struts at the front and an H-shaped torsion beam at the rear to keep the load floor low in order to increase luggage capacity. Front and rear stabilizer bars are also installed. On Insight EX models, the 175/65-15 low rolling resistance tires are mounted on very lightweight aluminum rims. Each tire and wheel together weigh only 34 pounds. The Insight's electrically-assisted, rack-and-pinion steering does not rely on an enginedriven, hydraulic power steering pump as in conventional non-hybrid vehicles. Electric assist improves fuel efficiency (less parasitic drag on the engine) and allows the Insight to steer normally even when the engine is shut off in Idle Stop mode. The Insight’s hydraulic braking system includes four-channel ABS (to prevent wheel lockup), Electronic Brake Distribution (to improve braking effectiveness under different vehicle loads), and a Creep Aid System (to prevent the car from rolling on a hill when the driver transitions from the brake pedal to the throttle pedal). Also included are Traction Control and Vehicle Stability Assist (the latter system employing an electronic yaw rate/lateral acceleration sensor to detect excessive understeer or oversteer when cornering). A Brake Booster Pressure Monitoring System continuously monitors boost vacuum when the engine is shut off during Idle Stop mode. The front brakes use a singlepiston sliding caliper and a one-piece ventilated rotor. The rear brakes are drum-type. In July 2010, Honda UK announced an update for the Insight to be released in September. The update comprising suspension changes are a response to feedback of the Insight's ride and handling. There are revisions to the recoil rate of the springs, change of the rear camber angles and alterations to the rear suspension brace and adjusting mounts. As a result, Honda promised better ride, handling and stability. Interior changes were also made: dashboard and seat fabric colours have been revised, as have some of the interior plastics, now higher in quality. The air vents received a chrome surround and a silver garnish now adorns the door sills.

Enhanced efficiency air conditioning system The air conditioning system on the new Insight has an expanded thermodynamic range compared to conventional systems. Unlike the separate low pressure and high pressure refrigerant pipes used in conventional systems, the Insight has its low pressure cold pipe enclosing the high pressure hot refrigerant pipe that allows the cold refrigerant on its way back to the engine bay to cool the warm refrigerant travelling to the cabin. A unique, spiral groove along the outside of the inner pipe increases the surface area and therefore the efficiency of the heat transfer between the outer and inner tubes. This improves the thermal efficiency of the air-conditioning system and, as a result, less effort is required from the compressor, resulting in improved fuel efficiency. In order to control costs, Honda decided not to include the electric-assist air conditioning compressor used in the Civic Hybrid. The Civic Hybrid's electric-assist allows the air conditioning compressor to continue running (using battery pack power) to maintain cabin temperature when the engine is shut off in Idle Stop mode. Instead, the Insight

limits the duration of the Idle Stop mode during air conditioning use and restarts the engine, when needed, to maintain cabin temperature. However, when the Insight's ECON function is engaged, a longer Idle Stop time is invoked for improved fuel efficiency at the expense of rapid cabin cooling.

Multi-information display The Multi-information display, located in the center of the tachometer, can be toggled through nine different screens of vehicle information including instantaneous fuel economy, hybrid system schematic, trip computer, and ECO Guide. The ECO Guide display includes a real-time graphic that provides a target zone for acceleration and deceleration in order to achieve maximum fuel economy. When the ignition switch is turned off, a summary screen displays a scoring function that encourages drivers to take an interest in developing fuel-efficient driving habits over the long term. In this manner, drivers can earn additional ‘leaves’ on a plant stem when practicing fuel saving strategies. Long-term fuel efficient driving habits ultimately earn the driver a ‘trophy’ graphic.

Sales and prices by country Honda sold 130,445 Insights worldwide in 2009. Japan The new Insight began sales in Japan on February 6, 2009 with prices between ¥1,890,000 and ¥2,210,000.The reception in Japan is overwhelming and exceeds Honda's original forecast of 5,000 monthly sales. This resulted as less availability to overseas markets and Honda has to start production on a second line at its Suzuka factory in midJune to increase production from 700 units a day. In April 2009, the Honda Insight became the first gas-electric hybrid to be the best-selling vehicle in Japan for the month. After less than eleven months on sale, Honda sold 93,283 Insight in Japan in 2009, ranking it the fifth best-selling car for the year. In March 2010, Honda announced that the new Insight broke through 100,000 sales in Japanese market in just one year after its introduction.

U.S. Honda Insight, shown front, rear, and the hybrid badging. United States The car went on sale on March 24, 2009 in the U.S. as a 2010 model with MSRP prices between US$19,800 and US$23,200, making it the least expensive hybrid vehicle available in the United States. Within less than ten months from its introduction, Insight total sales for 2009 in the U.S. market were 20,572 units, selling more than the Fusion Hybrid (15,554 units) and the Civic Hybrid (15,119), but behind the Camry Hybrid (22,887 units) and the Toyota Prius (139,682 units). In August 2010 the Insight reached cumulative sales in the U.S. market of 14,145 units, ranking as the third most sold hybrid in 2010 after the Toyota Prius (91,940 units) and the Ford Fusion Hybrid (14,604 units). In December 2010, Honda introduced a less expensive Insight hybrid for the 2011 model year to help boost sales. The new base model Insight will start at a MSRP of US$18,200, US$1,600 less expensive than the previous lowest trim level, the LX. For the 2011 LX model, center armrest, cruise control, USB connectivity for the audio system and floor mats are newly added. Price increase is limited to US$100. Electronic stability control and brake assist are now standard across all trim levels. All models come with automatic climate control. Honda explained the move "to make (the vehicle) more affordable for those younger customers who couldn't previously get into a hybrid." In 2009, Toyota

promised a lower-priced version of the Prius to compete with Insight, but quietly dropped the deal for consumers. Calendar Year American sales 2009 20,572

In October 2009, Consumer Reports named Honda Insight the most reliable vehicle as it scored the highest of any vehicles in predicted reliability, according to its annual vehicles reliability survey. United Kingdom The Honda Insight has been on sale from April 4, 2009 and early report said it outsold its competitor by 15 percent. The Insight is exempted from the London congestion charge. Starting from autumn 2010, parking sensors are added to ES model and above, furthermore, a top of the range EX model is added with standard leather interior and satnav priced at £20,215. Australia It is reported that Honda is going to launch Insight in the second half of 2010. Honda Australia is reported to aim at pricing the Insight at below A$30,000, which would means it will be much more affordable than the Toyota Prius that starts at A$39,990. However, the price is contingent on the future strength of the Australian dollar, according to Lindsay Smalley of Honda Australia. The Netherlands As of March 2010, Honda has sold 2661 units since the introduction of the Insight in April 2009. Of which, 847 were sold in the first 3 months of 2010. As of January 2010, the Honda Insight is exempt of road tax. Reviews have been mostly positive, praising the low cost, fuel economy, good handling and performance in city driving, while being somewhat critical of the car's performance on the highway and its rear visibility. Particularly impressive is the high vehicle safety rating. The EuroNCAP judged the Insight the second safest car of 2009, just behind the Volkswagen Golf but ahead of its main rival, the Toyota Prius. The sales of the Honda Insight, along with those of the Honda Civic Hybrid, helped Honda achieve their best sales result in the Netherlands since 1989. These good results did not go unnoticed and it has been decided that the official European launch of Honda's next hybrid car, the CR-Z, will take place in the Netherlands. Other Asian countries Honda Insight is launched in Korea in October 2010 priced at Won29.5 million (approx. US$ 26,000), making it the lowest priced hybrid car offered by import automakers.

In Malaysia, Honda launched the Insight on December 2, 2010 at the Kuala Lumpur International Motor Show (KLIMS) 2010. Priced at RM98,000 OTR including insurance, the Insight became the first affordable hybrid that is priced below RM100,000. It is priced only RM7,520 more than the top model of Honda City. It is reported that a few hundred sales orders were received even before its launch.

Reception

Second generation Honda Insight engine. Early reviews praised the Insight's futuristic styling, handling, and price but noted that it was less powerful, less fuel efficient, and less comfortable than other more expensive hybrids. The Insight performed well in comparison tests administered by Motor Trend

and Car and Driver. In their comparison test against the 2010 Toyota Prius, Car and Driver stated "...the Insight proved more visceral, connected, and agile than the Prius. The Insight represents a lot of engineering bang for the buck, and the majority of its dynamics are more satisfying than the Prius’s" citing the benefits of the Insight's firm brake feel, accurate steering, and tight suspension (the latter borrowing heavily from the latest Honda Fit). It did not perform as well in Edmunds or Popular Mechanics tests. In Consumer Reports testing the Insight was assigned a low score, stating that it fell short in ride quality, handling, interior noise, acceleration, refinement, rear seat access and rear visibility. Autoblog praised it for its fuel economy, tight handling, and good steering feedback, and stated "the Insight is a shockingly fun car to drive in a spirited manner in spite of the comparatively modest thrust available.", but criticized the Insight for its low passenger volume. Automotive critic Jeremy Clarkson, known for his disdain for hybrid vehicles, criticized the Insight for its continuously variable transmission, engine noise, and build quality. He recognized that the price was low, but concluded that a Volkswagen Golf is a better deal. He remarked that the Insight is "possibly the worst new car money can buy", and awarded it one out of five stars. Edmunds.com praised Insight for improving upon the formula of rival Prius and costing thousands less, but criticized it for excessive road noise, a tight back seat, and buzzy engine under hard acceleration. In addition, they state it "is by far the most enjoyable hybrid hatchback to drive" and praised the ride for being firm, the steering for being relatively responsive, and the seamless integration between the electric and gas motor. In 2009, Edmunds pitted a Honda Insight against other hybrids like Toyota Prius and Fusion hybrid, a VW Jetta TDI automatic and a MINI Cooper with manual transmission over two days of mixed city and highway driving.

Driving condition

2010 Toyota Prius

2010 Honda Insight

2009 VW Jetta TDI A6

2010 Ford Fusion Hybrid

2009 MINI Cooper M6

Back roads

47.2

44.1

41.2

39.6

38.5

City loop

48.7

43.4

31.6

35.1

30.1

Highway

47.4

38.6

40.6

36.0

33.3

Overall

47.6

42.3

38.1

37.3

34.5

EPA City/Hwy

51/48

40/43

29/40

41/36

28/37

Crash test Insurance Institute for Highway Safety: • •

Frontal Offset test: Good Side Impact test: Good

Europe NCAP: •

Awarded

stars

Awards and recognition • • • •

• • •

The second generation Insight is awarded 2009 Good Design Award from the Japan Industrial Design Promotion Organization The American Automobile Association (AAA) awarded the Honda Insight II the top commuter vehicle in 2010. Selected among Kelley Blue Book Top 10 Green Cars for 2010 The first generation Insight's engine won the International Engine of the Year award for 2000, and continued to hold the "Sub-1 liter" size category for the next six years. It received the U.S. Environmental Protection Agency's 2000 Climate Protection Award. It was named the "Greenest Vehicle" of the year for 2000, 2002, 2003 and 2006 by the American Council for an Energy-Efficient Economy (ACEEE). The Insight was nominated for the North American Car of the Year award for 2001.

Chapter- 6

Corporate Average Fuel Economy

The Corporate Average Fuel Economy (CAFE) are regulations in the United States, first enacted by US Congress in 1975, and intended to improve the average fuel economy of cars and light trucks (trucks, vans and sport utility vehicles) sold in the US in the wake of the 1973 Arab Oil Embargo. Historically, it is the sales-weighted harmonic mean fuel economy, expressed in miles per gallon (mpg), of a manufacturer's fleet of current model year passenger cars or light trucks with a gross vehicle weight rating (GVWR) of 8,500 pounds (3,856 kg) or less, manufactured for sale in the US. This system would have changed with the introduction of "Footprint" regulations for light trucks binding in 2011, but the 9th Circuit Court of Appeals returned that rule for reconsideration for, among other things, being "arbitrary and capricious". The most recent revision of CAFE that passed in 2007 no longer exempts light trucks classified as SUVs or passenger vans, unless they exceed 10,000 lb (4,500 kg) GVWR; it applies to pickup trucks and cargo vans up to 8,500 lb (3,900 kg) – as was the case for SUVs. In 1999, over half a million vehicles exceeded the GVWR and so the CAFE standard did not apply. In 2011, the standard will change to include many larger vehicles. The US and Canada have the weakest standards in terms of fleet-average fuel economy rating among first world nations, e.g. 25 mpg in the US, versus 45 mpg in the European Union and higher in Japan (2008). However, the US and Canada have the toughest emissions requirements (in terms of parts per million of pollutants). Some higher-mileage vehicles in Europe would not meet US (and California) emissions standards. The National Highway Traffic Safety Administration (NHTSA) regulates CAFE standards and the US Environmental Protection Agency (EPA) measures vehicle fuel efficiency. US Congress specifies that CAFE standards must be set at the "maximum feasible level" given consideration for: 1. technological feasibility; 2. economic practicality; 3. effect of other standards on fuel economy;

4. need of the nation to conserve energy. Historically, the EPA has encouraged consumers to buy more fuel efficient vehicles, while the NHTSA expressed concerns that smaller, more fuel efficient vehicles may lead to increased traffic fatalities. Thus higher fuel efficiency was associated with lower traffic safety, intertwining the issues of fuel economy, road-traffic safety, air pollution, and climate change. In the mid 2000s, increasing safety of smaller cars and the poor safety record of light trucks began to reverse this association. If the average fuel economy of a manufacturer's annual fleet of car and/or truck production falls below the defined standard, the manufacturer must pay a penalty, currently $5.50 USD per 0.1 mpg under the standard, multiplied by the manufacturer's total production for the U.S. domestic market.

Effect on automotive fuel economy

Prices inflation adjusted to 2008 dollars. In 2002, a committee of the National Academy of Sciences wrote a report on the effects of the CAFE standard. The report's conclusions include a finding that in the absence of CAFE, and with no other fuel economy regulation substituted, motor vehicle fuel consumption would have been approximately 14 percent higher than it actually was in 2002. One cost of this increase in fuel economy is a possible increase in fatalities, estimated to be 1,300 to 2,600 increased fatalities in 1993, albeit with certain of the committee members dissenting. A plot of average overall vehicle fuel economy (CAFE) for new model year passenger cars, the required by law CAFE standard target fuel economy value (CAFE standard) for new model year passenger cars, and fuel prices, adjusted for inflation, shows that there

has been little variation over the past 20 years. Within this period, there are three distinct periods of fuel economy change: 1. from 1979-1982 the fuel economy rose as the CAFE standard rose dramatically and the price of fuel increased; 2. from 1984-1986 the fuel economy rose as the CAFE standard rose as the price of fuel decreased rapidly; 3. from 1986-1988 the fuel economy rose at a significantly subdued rate and eventually leveled off as the price of fuel fell and the CAFE standard was relaxed before returning to 1986 levels in 1990. These are following by an extended period during which the passenger car CAFE standard, the observed average passenger car fuel economy, and the price of gasoline remained stable, and finally a period starting about 2003 when prices rose dramatically and fuel economy has slowly responded. Simple economics would predict that an increase in gasoline prices would lead in the long run to an increase in the average fuel economy of the US passenger car fleet, and that a drop in gasoline prices would be associated with a reduction in the average fuel economy of the entire US fleet. There is some evidence that this happened with an increase in market share of lower fuel economy light trucks and SUVs and decline in passenger car sales, as a percentage of total fleet sales, as car buying trends changed during the 1990s, the impact of which is not reflected in this chart. In the case of passenger cars, US average fuel economy did not fall as economic theory would predict, suggesting that CAFE standards maintained the higher fuel economy of the passenger car fleet during the long period from the end of the 1979 energy crisis to the rise of gasoline prices in the early 2000s. Most recently, fuel economy has increased about one mpg from 2006 to 2007. This increase is due primarily to increased fuel efficiency of imported cars. Similarly, Simple Economics predicts that due to the US's large percentage consumption of the world's oil supply, that increasing fuel economy would drive down the gasoline prices that US consumers would otherwise have to pay—reductions in petroleum demand in the United States helped create the collapse of OPEC market power in 1986. The "CAFE" and "CAFE standard" shown here only regards new model passenger car fuel economy and target fuel economy (respectively) rather than the overall US fuel economy average which tends to be dominated by used vehicles manufactured in previous years, new model light truck CAFE standards, light truck CAFE averages, or aggregate data.

Calculation Fleet fuel economy is calculated using a harmonic mean, not a simple arithmetic mean (average) – namely, the reciprocal of the average of the reciprocal values. For a fleet composed of four different kinds of vehicle A, B, C and D, produced in numbers nA, nB, nC and nD, with fuel economies fA, fB, fC and fD, the CAFE would be:

For example, a fleet of 4 vehicles getting 15, 13, 17, and 100 mpg has a CAFE of slightly less than 19 mpg:

While the arithmetic mean fuel economy of the fleet is just over 36 mpg:

The harmonic mean captures the fuel economy of driving each car in the fleet for the same number of miles, while the arithmetic mean captures the fuel economy of driving each car using the same amount of gas (i.e. the 13 mpg vehicle would travel 13 miles with one gallon while the 100 mpg vehicle would travel 100 miles). For the purposes of CAFE, a manufacturer's car output is divided into a domestic fleet (vehicles with more than 75 percent U.S., Canadian or post-NAFTA Mexican content) and a foreign fleet (everything else). Each of these fleets must separately meet the requirements. The two-fleet requirement was developed by the United Automobile Workers (UAW) as a means to ensure job creation in the US. The UAW successfully lobbied Congress to write this provision into the enabling legislation – and continues to advocate this position. The two fleet rule for light trucks was removed in 1996. For the fuel economy calculation for alternative fuel vehicles, a gallon of alternative fuel is deemed to contain 15% fuel (which is approximately the amount of gasoline in a gallon of E85) as an incentive to develop alternative fuel vehicles. The mileage for dual-fuel vehicles, such as E85 capable models, is computed as the average of its alternative fuel rating—divided by 0.15 (equal to multiplying by 6.666) -- and its gasoline rating. Thus an E85-capable vehicle that gets 15 mpg on E-85 and 25 mpg on gasoline might logically be rated at 20 mpg. But in fact the average, for CAFE purposes, despite perhaps only one percent of the fuel used in E85-capable vehicles is actually E85, is computed as 100 mpg for E-85 and the standard 25 mpg for gasoline, or 62.5 mpg. However, the total increase in a manufacturer's average fuel economy rating due to dual-fueled vehicles cannot exceed 1.2mpg. Manufacturers are also allowed to earn CAFE "credits" in any year they exceed CAFE requirements, which they may use to offset deficiencies in other years. CAFE credits can be applied to the three years before or after the year in which they are earned. The reason for this flexibility is so manufacturers are penalized only for persistent failure to meet the requirements, not for transient non-compliance due to market conditions.

Historical standards Fuel economy regulations were first introduced in 1978, only for passenger vehicles. The next year, a second category was defined for light trucks. These were distinguished from heavy duty vehicles by a gross vehicle weight rating (GVWR) of 6000 pounds or less. The GVWR threshold was raised to 8500 pounds in 1980 and has remained at that level through 2007. Thus certain large trucks and SUV's are exempt, such as the Hummer and the Ford Excursion. From 1979-1991, separate standards were established for two wheel drive (2WD) and four wheel drive (4WD) light trucks, but for most of this period, car makers were allowed to choose between these separate standards or a combined standard to be applied to the entire fleet of light trucks they sold that model year. In 1980 and 1981, respectively, a manufacturer whose light truck fleet was powered exclusively by basic engines which were not also used in passenger cars could meet standards of 14 mpg and 14.5 mpg. CAFE standards in miles per gallon for each model year from 1978-2011. In the early years, standards for the light trucks were optionally distinguished by drive train; only the combined option is shown here. CAFE standards for each model year in miles per gallon. Model Year

Passenger Cars

Light Trucks 2WD

4WD

Combined

17.2

1978

18.0

1979

19.0

17.2

15.8

1980

20.0

16.0

14.0

1981

22.0

16.7

15.0

1982

24.0

18.0

16.0

17.5

1983

26.0

19.5

17.5

19.0

1984

27.0

20.3

18.5

20.0

1985

27.5

19.7

18.9

19.5

1986

26.0

20.5

19.5

20.0

1987

26.0

21.0

19.5

20.5

1988

26.0

21.0

19.5

20.5

1989

26.5

21.5

19.0

20.5

1990

27.5

20.5

19.0

20.0

1991

27.5

20.7

19.1

20.2

1992

27.5

20.2

1993

27.5

20.4

1994

27.5

20.5

1995

27.5

20.6

1996

27.5

20.7

1997

27.5

20.7

1998

27.5

20.7

1999

27.5

20.7

2000

27.5

20.7

2001

27.5

20.7

2002

27.5

20.7

2003

27.5

20.7

2004

27.5

20.7

2005

27.5

21.0

2006

27.5

21.6

2007

27.5

22.2

2008

27.5

22.5

2009

27.5

23.1

2010

27.5

23.5

2011

30.2

24.1

Since 1980, the traditional Japanese manufacturers have increased their combined fleet average fuel economy by 1.6 miles per gallon according to the March 30, 2009 Summary of Fuel Economy Performance published annually by NHTSA. During this time, they also increased their sales in the US by 221%. The traditional European manufacturers actually decreased their fleet average fuel economy by 2 miles per gallon while increasing their sales volume by 91%. The traditional US manufacturers, Chrysler, Ford and General Motors, increased their fleet average fuel economy by 4.1 miles per gallon since 1980 according to the latest government figures. During this time the sales of US manufacturers decreased by 29%.

Current standards

Cars and light trucks are considered separately for CAFE and are held to different standards. As of early 2004, the average for cars must exceed 27.5 mpg, and the light truck average must exceed 20.7 mpg. Trucks under 8500 pounds must average 22.5 mpg in 2008, 23.1 mpg in 2009, and 23.5 mpg in 2010. After this, new rules set varying targets based on truck size "footprint." In late 2007, CAFE standards received their first overhaul in more than 30 years. On December 19, President Bush signed into law the Energy Independence and Security Act of 2007, which requires in part that automakers boost fleetwide gas mileage to 35 mpg by the year 2020. This requirement applies to all passenger automobiles, including "light trucks." Politicians had faced increased public pressure to raise CAFE standards; a July 2007 poll conducted in 30 congressional districts in seven states revealed 84-90% in favor of legislating mandatory increases. Overall fuel economy for both cars and light trucks in the U.S. market reached its highest level in 1987, when manufacturers managed 26.2 mpg (8.98 L/100 km). The average in 2004 was 24.6 mpg. In that time, vehicles increased in size from an average of 3,220 pounds to 4,066 pounds (1,461 kg to 1,844 kg), in part due to an increase in truck ownership during that time from 28% to 53%. A number of manufacturers choose to pay CAFE penalties rather than attempt to comply with the regulations. As of model year 2006, BMW, DaimlerChrysler, Volkswagen, Ferrari, Porsche and Maserati failed to meet CAFE requirements. For the 2008 model year, Mercedes-Benz had the lowest fleet average while Lotus had the highest.

Future The effect of Energy Independence and Security Act on CAFE standards On December 19, 2007, President George W. Bush signed the Energy Independence and Security Act. This Act aims at improving vehicle fuel economy. The Act set a goal for the national fuel economy standard of 35 miles per gallon (mpg) by 2020. This would increase the fuel economy standards by 40 percent and save the United States billions of gallons of fuel. This standard is the first standard that has been set above the Corporate Average Fuel Economy standards (CAFE) since it was created in 1975. CAFE standards since 1975 have increased very slowly till date. In 1978, the CAFE standard for passenger cars was 18.0mpg. At the time of the signing of the Energy Independence and Security Act (EISA) in 2007, the standard for passenger cars was 27.5mpg which was the same as the standard that was set in 1990. This has been the peak standard for passenger cars. This peak standard was first set in 1985 and then it was lowered to 26mpg in 1986 and got back to the peak again in 1990. The combined standard for light trucks experienced a much more gradual increase from 17.5mpg in 1982 to 22.2mpg in 2007. The light truck Average Fuel Economy Standards for model

years (MY) 2005 to 2007 were 21.0mpg for MY2005, 21.6mpg for MY2006 and 22.2mpg for MY2007. In 2006, the rule making for light trucks for model years 2008 2011 included a reform to the structure for CAFE standards for light truck and gave manufacturers the option for model years 2008-2010 to comply with the reformed standard or to comply with the unreformed standard. The reformed standard was based on the vehicle foot print. The unreformed standard for 2008 was set to be 22.5mpg. To achieve the target of 35mpg authorized under EISA for the combined fleet of passenger cars and light truck for MY2020, NHTSA is required to continue raising the CAFE standards.In determining a new CAFE standard, NHTSA must assess the environmental impacts of each new standard and the effect of this standard on employment. With the EISA, NHTSA needed to take new analysis including taking a fresh look at the potential impacts under the National Environmental Policy Act (NEPA) and assessing whether or not the impacts are significant within the meaning of NEPA. NHTSA has to issue its new standards eighteen months before the model year for fleet. According to NHTSA report, in order to achieve this industry wide combined fleet of at least 35mpg, NHTSA must set new standards well in advance of the model year so as to provide the automobile manufacturers with lead time enough to make extensive necessary changes in their automobiles. The EISA also called for a reform where the standards set by the Transportation Department would be are “attribute based” so as to ensure that the safety of vehicles is not compromised for higher standards.

New CAFE credit trading provisions CAFE changes enacted by the 110th Congress (The Energy Independence and Security Act P.L. 110-140, H.R. 6), instructed NHTSA to establish a credit trading and transferring scheme to allow manufacturers to transfer credits between categories, as well as sell them to other manufacturers or non-manufacturers. In addition, the period over which credits could be carried forward was extended from three years to five. Traded or transferred credits may not be used to meet the minimum standard in the domestic passenger car fleet, however they may be used to meet the `attribute standard'. This latter allowance has drawn criticism from the UAW which fears it will lead manufacturers to increase the importation of small cars to offset shortfalls in the domestic market. These new flexibilities were implemented by regulation on March 23, 2009 in the Final Rule for 2011 Model Year Passenger Cars and Light Trucks. Calculations using official CAFE data, and the newly proposed credit trading flexibility contained in the September 28, 2009 Notice of Proposed Rulemaking show that ninetyeight percent of the benefit derived from just the cross fleet credit trading provision flows to Toyota. According to these calculations 75% of the benefit from the two new CAFE credit trading provisions, cross fleet trading and 5-year carry-forward, falls to foreign manufacturers. Toyota can use the provision to avoid or reduce compliance on average by 0.69 mpg per year through 2020,

• • • • • • • •

Hyundai (1.01 mpg), Nissan (0.65), Honda (0.83 mpg), Mitsubishi (0.13 mpg), Subaru (0.08), Chrysler (0.14 mpg), GM (0.09 mpg), and Ford (0.18 mpg) also benefit.

The estimated value of the CAFE exemption gained by Toyota is $2.5 billion; Honda’s benefit is worth $0.8 billion, and Nissan’s benefit is valued at $0.9 billion in reduced CAFE compliance costs. Foreign companies gained $5.5 billion in benefits compared with the $1.8 billion that went to the Detroit Three.

Future

NHTSA data as from 20 June 2007 The CAFE rules for trucks were officially amended at the end of March 2006. However, the 9th Circuit Court of Appeals has overturned the rules, returning them to NHTSA, stating that the rules must be made stricter. These changes would have segmented truck fleets by vehicle size and class as of 2011. All SUVs and passenger vans up to 10,000 pounds GVWR would have had to comply with CAFE standards regardless of size, but pickup trucks and cargo vans over 8500 pounds gross vehicle weight rating (GVWR) would have remained exempt.

Under the new final light truck CAFE standard 2008-2011, fuel economy standards would have been restructured so that they are based on a measure of vehicle size called "footprint," the product of multiplying a vehicle's wheelbase by its track width. A target level of fuel economy would have been established for each increment in footprint using a continuous mathematical formula. Smaller footprint light trucks had higher fuel economy targets and larger trucks lower targets. Manufacturers who made more large trucks would have been allowed to meet a lower overall CAFE target, manufacturers who make more small trucks would have needed to meet a higher standard. Unlike previous CAFE standards there was no requirement for a manufacturer or the industry as a whole to meet any particular overall actual MPG target, since that will depend on the mix of sizes of trucks manufactured and ultimately purchased by consumers. Some critics pointed out that this might have had the unintended consequence of pushing manufacturers to make ever-larger vehicles to avoid strict economy standards. However, the equation used to calculate the fuel economy target had a built in mechanism that provides an incentive to reduce vehicle size to about 52 square feet (the approximate midpoint of the current light truck fleet.) The Ninth Circuit Court of Appeals found these new Light Truck rules to be arbitrary and capricious; contrary to the Energy Policy and Conservation Act; incorrectly set a value of zero dollars to the global warming damage caused by truck emissions; failed to set a "backstop" to prevent trucks from emitting more CO2 than in previous years; failed to set standards for vehicles in the 8,500 to 10,000 lb (4,500 kg) range; that the environmental impact assessment was inadequate, and that the rules may have had significant negative impact on the environment. The court directed NHTSA to prepare a new standard as quickly as possible and to fully evaluate that new standard's impact on the environment. In addition to the new light truck rules of 2006 and the Ninth Court decision, in December 2007 Congress passed the Energy Independence and Security Act of 2007 which will affect CAFE standards of both cars and trucks and additionally work trucks and medium and heavy duty on-highway vehicles. This standard requires ratable increases in fuel efficiency during the model years 2011 to 2020 reaching 35 mpg in 2020 for the total fleet of passenger and non-passenger automobiles. In the years 2021 to 2030 the standards requires MPG to be the "maximum feasible" fuel economy. The law allows NHTSA to issue additional requirements for cars and trucks based on the "footprint" model or other mathematical standard. Additionally each manufacturer must meet a minimum standard of the higher of either 27.5 mpg for passenger automobiles or 92% of the projected average for all manufacturers. National Highway Traffic Safety Administration (NHTSA) is directed based on National Academy of Sciences studies to set medium and heavy-duty truck MPG standards to the "maximum feasible". Additionally the law phases out the mpg credit previously granted to E85 flexible-fuel vehicle manufacturers and adds in one for biodiesel, and it adds a requirement that NHTSA publish replacement tire fuel efficiency ratings. The bill also adds support for initial state and local infrastructure for plug-in electric vehicles. How the Ninth Court decision will be reconciled to this new law remains undecided, but if the court issue is resolved and the new law goes into effect and if actual achieved combined corporate

CAFE remains at 26.7 mpg until then, then average fleet-wide new vehicle mpg would increase by 0.8 mpg a year starting in 2011. On April 22, 2008 NHTSA responded to this Energy Independence and Security Act of 2007 with proposed new fuel economy standards for cars and trucks effective model year 2011. It is not clear how the 9th Circuit Court of Appeals case will interact with these new rules. The new rules also introduce the "footprint" model for cars as well as trucks, where if a manufacturer makes more large cars and trucks they will be allowed to meet a lower standard for fuel economy. This means that an overall fuel efficiency for a particular manufacturer nor the fleet as a whole cannot be predicted with certainly since it will depend on the actual product mix manufactured. However, if the product mix is as NHTSA predicts, car fuel economy would increase from a current standard of 27.5 mpgUS (8.55 L/100 km; 33.0 mpg-imp) to 31.0 mpg-US (7.59 L/100 km; 37.2 mpg-imp) in 2011. The new regulations are designed to be "optimized" with respect to a certain set of assumptions which include: gas prices in 2016 will be $2.25 a U.S. gallon (59.4¢/L), all new car purchasers will pay 7% interest rates on their vehicles purchases, and only care about fuel costs for the first 5 years of a vehicle's life, and that the value of global warming is $7 per ton CO2. This corresponds to a global warming value of $4.31 savings a year per car under the new regulations. Further, the new regulations assume that no advanced hybrids (Toyota Prius), plug-in hybrids and extended range electric vehicles (Chevrolet Volt), electric cars (Th!nk City), nor alternative fuel vehicles (Honda Civic GX) will be used to achieve these fuel economies. The new rules also propose again that California (and the other States following California's lead) be stripped of their historic right to set their own more stringent automotive air pollution standards. On January 26, 2009, President Barack Obama directed the Department of Transportation to review relevant legal, technological, and scientific considerations associated with establishing more stringent fuel economy standards, and to finalize the 2011 model year standard by the end of March. This single-model year standard was issued March 27, 2009 and is about one mpg lower than the fuel economy standards previously recommended under the Bush Administration. "These standards are important steps in the nation's quest to achieve energy independence and bring more fuel efficient vehicles to American families," said Secretary LaHood. The new standards will raise the industrywide combined average to 27.3 miles per US gallon (8.62 L/100 km; 32.8 mpg-imp) (a 2.0 mpg-US (2.4 mpg-imp) increase over the 2010 model year average), as estimated by the National Highway Traffic Safety Administration (NHTSA). It will save about 887,000,000 U.S. gallons (3.36×109 L) of fuel and reduce carbon dioxide emissions by 8.3 million metric tons. This 2011 single-year standard will use an attribute-based system, which sets fuel economy standards for individual vehicle models, based on the "footprint" model. Secretary LaHood also noted that work on the multi-year fuel economy plan for model years after 2011 is already well underway. The review will include an evaluation of fuel saving technologies, market conditions and future product plans from the manufacturers. The effort will be coordinated with interested stakeholders and other federal agencies, including the Environmental Protection Agency. The news rules were immediately challenged in court again by the Center for Biological Diversity as not addressing the inadequacies found by the previous court rulings. The interaction

between these future rules, the collapse of the auto industry in the United States, the listing by EPA on March 20, 2009 of CO2 as a global warming pollution dangerous to human welfare, and the willingness indicated by environmental groups to apply once again to the courts for a ruling that these standards are inadequate, again left the future of fuel economy standards in the United States in doubt. On May 19, 2009 President Barack Obama proposed a new national fuel economy program which adopts uniform federal standards to regulate both fuel economy and greenhouse gas emissions while preserving the legal authorities of DOT, EPA and California. The program covers model year 2012 to model year 2016 and ultimately requires an average fuel economy standard of 35.5 miles per US gallon (6.63 L/100 km; 42.6 mpg-imp) in 2016 (of 39 miles per gallon for cars and 30 mpg for trucks), a jump from the current average for all vehicles of 25 miles per gallon. Obama said, "The status quo is no longer acceptable." The result is a projected reduction in oil consumption of approximately 1.8 billion barrels over the life of the program and a projected total reduction in greenhouse gas emissions of approximately 900 million metric tons. Ten car companies and the UAW embraced the national program because it provides certainty and predictability to 2016 and includes flexibilities that will significantly reduce the cost of compliance. Stated goals for the program included: saving consumers money over the long term in increased fuel efficiency, preserving consumer choice—the new rules do not dictate the size of cars, trucks and SUVs that manufacturers can produce; rather it requires that all sizes of vehicles become more energy efficient, reduced air pollution in the form of greenhouse gas emissions and other conventional pollutants, one national policy for all automakers, instead of three standards (a DOT standard, an EPA standard and a California standard that would apply to 13 other states), and industry desires: clarity, predictability and certainty concerning the rules while giving them flexibility on how to meet the expected outcomes and the lead time they need to innovate. The new policy will result in yearly 5% increases in efficiency from 2012 through 2016, 1.8 Billion barrels of oil saved cumulatively over the lifetime of the program and significant reductions in greenhouse gas emissions equivalent to taking 177 million of today's cars off the road. There are a large number of technologies that manufacturers can apply to improve fuel efficiency short of implementing hybrid or plug-in hybrid technologies. Applied aggressively, at a cost of several thousand dollars per vehicle, the Union of Concerned Scientists estimates that these technologies can almost double MPG. Some technologies, such as four valves per cylinder, are already widely applied in cars, but not trucks. Manufacturers dispute how effective these technologies are, their retail price, and how willing customers are to pay for these improvements. Payback on these improvements is highly dependent on fuel prices.

Active debate CAFE does not directly offer incentives for customers to choose fuel efficient vehicles, nor does it directly affect fuel prices. Rather, it attempts to accomplish these goals

indirectly by making it more expensive for automakers to build inefficient vehicles by introducing penalties. The conservative Heartland Institute contends that CAFE standards do not work economically to consumers' benefit, that smaller cars are more likely to be damaged in a collision, and that insurance premiums for them are higher than for many larger cars. However, the Insurance Companies' Highway Loss Data Institute publishes data showing that larger vehicles are more expensive to insure. CAFE advocates assert most of the gains in fuel economy over the past 30 years can be attributed to the standard itself, while opponents assert economic forces are responsible for fuel economy gains, where higher fuel prices drove customers to seek more fuel efficient vehicles. CAFE standards have come under attack by some conservative think tanks, along with safety experts, car and truck manufacturers, some consumer and environment groups, and organized labor.

Effect on traffic safety Historically, NHTSA has expressed concerns that automotive manufacturers will increase mileage by reducing vehicle weight, which might lead to weight disparities in the vehicle population and increased danger for occupants of lighter vehicles. However, vehicle safety ratings are now made available to consumers by NHTSA and by the Insurance Institute for Highway Safety. A National Research Council report found that the standards implemented in the 1970s and 1980s "probably resulted in an additional 1,300 to 2,600 traffic fatalities in 1993. A Harvard Center for Risk Analysis study found that CAFE standards led to "2,200 to 3,900 additional fatalities to motorists per year. The Insurance Institute for Highway Safety's 2007 data show a correlation of about 250-500 fatalities per year per MPG. Proponents of higher CAFE standards argue that it is the "Footprint" model of CAFE for trucks that encourages production of larger trucks with concomitant increases in vehicle weight disparities, and point out that some small cars such as the Mini Cooper and Toyota Matrix are four times safer than SUVs like the Chevy Blazer. They argue that the quality of the engineering design is the prime determinant of vehicular safety, not the vehicle's mass. In a 1999 article based on a 1995 IIHS report, USA Today said that 56% of all deaths occurring in small cars were due to either single vehicle crashes or small cars impacting each other. The percentage of deaths attributed to those in small cars being hit by larger cars was one percent. In 2006, IIHS found that some of the smallest cars have good crash safety, while others do not, depending upon the engineering design. In a 2007 analysis, IIHS found that 50 percent of fatalities in small four-door vehicles were single vehicle crashes, compared to 83 percent in very large SUVs. The Mini Cooper had a fatality rate of 68 per million vehicle-years, compared to 115 for the Ford Excursion. A 2005 IIHS plot shows that in collisions between SUVs weighing 3,500 lb (1,600 kg) and cars, the car driver is more than 4X more likely to be killed, and if the SUV weighs over 5,000 lb (2,300 kg) the car driver is 9 times more likely to be killed, with 16 percent of deaths occurring in car-to-car crashes and 18 percent in car-to-truck crashes. Recent studies find about 75 percent of twovehicle fatalities involve a truck, and about half these fatalities involve a side-impact crash. Risk to the driver of the other vehicle is almost 10 times higher when the vehicle is a one ton pickup compared to an imported car. And a 2003 Transportation Research

Board study show greater safety disparities among vehicles of differing price, country of origin, and quality than among vehicles of different size and weight. These more recent studies tend to discount the importance of vehicle mass to traffic safety, pointing instead to the quality of engineering design as the primary factor.

Increased oil and automobile usage As fuel efficiency rises, people drive their cars more, which offsets some of the gains that might be had in carbon dioxide emissions from the higher standards. While driving more results from the increased economic benefit to consumers of higher efficiency vehicles, the National Academies Report (Page 19) estimates this "rebound effect" as reducing the gains from increased fuel economy by only 10-20 percent. It is also possible that because higher-efficiency vehicles are more expensive, auto buyers may choose to keep their older cars (some of which are less efficient) for longer before making a new purchase. However, associated costs, such as increased deaths, may be more than offset by savings on a global scale, because increased CAFE standards reduce reliance on increasingly expensive and unreliable sources of imported petroleum and lower the probability of global climate change by reducing US emissions of carbon dioxide.

Economic arguments In the May 6, 2007 edition of Autoline Detroit, Bob Lutz, a automobile designer/executive of BMW and Big Three fame, asserted that the CAFE standard was a failure and said it was like trying to fight obesity by requiring tailors to make only smallsized clothes. Proponents state that automobile-purchasing decisions that may have global effects should not be left entirely up to individuals operating in a free market. Automakers have said that small, fuel-efficient vehicles cost the auto industry billions of dollars. They cost almost as much to design and market but cannot be sold for as much as larger vehicles such as SUVs, because consumers expect small cars to be inexpensive. In 1999 USA Today reported small cars tend to depreciate faster than larger cars, so they are worth less in value to the consumer over time. However, 2007 Edmunds depreciation data show that some small cars, primarily premium models, are among the best in holding their value.

Automaker viewpoints & consumer preferences Historically, automakers and some conservative groups have believed consumers don't prioritize fuel economy. In 2003, Alliance of Automobile Manufacturers spokesman Eron Shosteck asserted automakers produce more than 30 models rated at 30 mpg or more for the US market, and they are poor sellers. In 2004, GM retiree Charles Amann said

statistically, consumers do not pick the weak-performing vehicle when given a choice of engines. However, after a spike in gas prices, a 2006 Consumer Reports survey concluded fuel economy is the most important consideration in consumers' choice of vehicle and a 2007 Pew Charitable Trusts survey found that nine out of ten Americans favor tougher CAFE standards, including 91% of Democrats and 85% of Republicans. In 2007, the 55 mpg Toyota Prius outsold the top-selling SUV, the 17 mpg Ford Explorer. In late 2007, GM Vice Chairman Bob Lutz called hybrid gasoline-electric vehicles the "ideal solution",. In 2008, GM advertised fuel economy improvements and their upcoming Chevrolet Volt Extended Range Electric Vehicle., and developed corporate branding for their fuel economy technologies, and though GM Chairman Rick Wagoner admitted he doesn't know which fuel efficiency technologies consumers really want he said "we are moving fast with technologies like E-85 (ethanol), all-electric, fuel cells and a wide range of hybrid offers." In 1999, automakers asserted they couldn't lobby for the repeal of CAFE standards, because consumers would learn small cars are unsafe and not buy them, or would try to sue the manufacturers. However, NHTSA's public record shows the automakers publicly express opposition to CAFE increases.

SUVs and minivans created due to original mandate The definitions for cars and trucks are not the same for fuel economy and emission standards. For example, a Chrysler PT Cruiser is defined as a car for emissions purposes and a truck for fuel economy purposes. Under the current light truck fuel economy rules, the PT Cruiser will have a higher fuel economy target (28.05 mpg beginning in 2011) than it would if it were classified as a passenger car. CAFE standards signaled the end of the traditional long station wagon, but legendary former Chrysler CEO Lee Iacocca developed the idea of marketing the minivan as a station wagon alternative, while certifying it in the separate truck category to allow compliance with less-strict emissions standards. Eventually, this same idea led to the promotion of the SUV. New York, New Jersey, Pennsylvania, Connecticut and California disagreed with the NHTSA statement in the 2008-2011 Light Truck standard which claimed preemption of the state greenhouse gas regulations, on the basis that fuel economy and carbon dioxide emissions are one and the same. The EPA claims, contrary to NHTSA, that the use of alternative fuels allows greenhouse gas emissions to be controlled somewhat independently of fuel efficiency.

Calculations of MPG overestimated The United States Environmental Protection Agency (EPA) laboratory measurements of MPG have consistently overestimated fuel economy of gasoline vehicles and underestimated diesel vehicles. John DeCicco, the automotive expert for the Environmental Defense Fund (EDF), estimated that this results in about 20% higher actual consumption than measured CAFE goals. Starting with 2008-model vehicles, the EPA has adopted a new protocol for estimating the MPG figures presented to consumers.

The new protocol includes driving cycles more closely representative of today's traffic and road conditions, as well as increased air conditioner usage. This change does not affect how the EPA calculates CAFE ratings; the new protocol changes only the mileage estimates provided for consumer information. NHTSA spends one-third of one percent of its budget on CAFE, or $0.014 per US citizen.

Low Penalty Some critics argue that CAFE fines do not seem to be having much impact in the fuel economy drive. As noted in the 2007 United States Government Accountability Office Report to the Chairman of the U.S. Senate Committee on Commerce, Science, and Transportation (page 23) "Several experts stated that this is (penalties) not enough of a monetary incentive for manufacturers to comply with CAFE." For example, in 25 years from 1983 to 2008 Mercedes-Benz paid penalties 21 times and BMW paid penalties 20 times. Currently CAFE penalty is $55 USD per vehicle for every 1 mpg under the standard. For the year 2006 Mercedes-Benz draw $30.3 million penalty for violating fuel economy standards. That equates to $122 per one sold vehicle (in 2006 Mercedes-Benz sales were 248,080 vehicles) A penalty of $122 means violating CAFE by 2.22 MPG ($122 divided by $55). According to the government "fueleconomy.gov" website violating CAFE by 2.42 MPG means consuming extra 27 barrels (1134 gallons) of mostly imported fuel in 10 years which is worth $3,490 (Based on 45% highway, 55% city driving, 15000 annual miles and a fuel price of $ 2.95 per gallon) that is 13.4% more and also it means emitting extra 14 Tons of CO2 in 10 years that is 12.7% more. These numbers are based on comparison of 2010 Mercedes ML 350 4MATIC with CAFE Unadjusted Average Fuel Economy of 21.64 MPG (this model meets 2006 CAFE requirements of 21.6 MPG) and 2010 Mercedes ML 550 4MATIC with CAFE Unadjusted Average Fuel Economy of 19.22 MPG. So consuming extra $3,490 worth of mostly imported fuel and emitting extra 14 Tons of CO2 draws a penalty of only $122 for a single luxury car buyer. $122 is only 0.3% of the price of $40,000 car (average 2010 price of a luxury car). Several experts stated that this is not enough of a monetary incentive to comply with CAFE. CAFE penalty have increased only 10% since 1983. At the same time inflation rate from 1983 to 2010 was 119.2%. It means that CAFE penalty in 2010 is actually 2 times less than what it was in 1983. NHTSA officials stated that, in addition to the authority the Federal Civil Penalties Inflation Adjustment Act of 1990 under EPCA, NHTSA has the authority to raise CAFE penalties to $100 per 1 mpg shortfall. NHTSA chooses not to exercise this authority.

Other arguments in favor Other conservative groups support higher gas mileage on the basis of national security, or on the basis of stewardship of the Earth.