Fuel efficiency relates the efficiency of converting energy contained in a carrier fuel to kinetic energy or work. Often this applies specifically in a transportation vehicle, such as an automobile. Fuel economy in automobiles relates to the amount of fuel required to move a vehicle over a given distance. While the fuel efficiency of petroleum engines has improved markedly in recent decades, this does not necessarily translate into fuel economy of cars, as people in developed countries tend to buy bigger and heavier cars. Fuel is a material with one type of energy which can be transformed into another usable energy. ... Kinetic jkljfkdffmdklcjenergy (SI unit: the [[klof its motion. ... Look up work in Wiktionary, the free dictionary. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... This article or section does not cite its references or sources. ... Fuel economy is the amount of fuel required to move a vehicle over a given distance. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The distance between two points is the length of a straight line segment between them. ... Pumpjack pumping an oil well near Sarnia, Ontario Petroleum (from Greek petra – rock and elaion – oil or Latin oleum – oil ) or crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish liquid. ... A colorized automobile engine The internal combustion engine is a heat engine in which the burning of a fuel occurs in a confined space called a combustion chamber. ... This article or section does not cite its references or sources. ... A developed country is a country that has achieved (currently or historically) a high degree of industrialization, and which enjoys the higher standards of living which wealth and technology make possible. ...

Other applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process. Mohave Generating Station, a 1,580 MW coal power plant near Laughlin, Nevada A fossil fuel power plant is an energy conversion center that combusts fossil fuels to produce electricity, designed on a large scale for continuous operation. ... Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ... The Haber Process (also Haber-Bosch process) is the reaction of nitrogen and hydrogen to produce ammonia. ...

Energy content of fuel

The British thermal unit (BTU or Btu) is a unit of energy used in the United States. ... The gallon (abbreviation: gal) is an English unit of volume. ... The octane rating is a measure of the autoignition resistance of gasoline (petrol) and other fuels used in spark-ignition internal combustion engines. ... Gasoline (or petrol) is a petroleum-derived liquid mixture consisting primarily of hydrocarbons, used as fuel in internal combustion engines. ... 45 kg LPG cylinders Liquified petroleum gas (also called liquefied petroleum gas, liquid petroleum gas, LPG, LP Gas, or autogas) is a mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles, and increasingly replacing fluorocarbons as an aerosol propellant and a refrigerant to reduce damage to... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless chemical compound, one of the alcohols that is most often found in alcoholic beverages. ... Methanol, also known as methyl alcohol or wood alcohol, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a very faint odor. ... It has been suggested that Bioalcohol be merged into this article or section. ... Diesel or Diesel fuel is a specific fractional distillate of fuel oil (mostly petroleum) that is used as fuel in a diesel engine invented by German engineer Rudolf Diesel. ... Cetane number or CN is to diesel fuel what octane rating is to gasoline. ...

Fuel economy

Main article: Fuel economy in automobiles

Fuel economy is usually expressed in one of two ways: Fuel economy is the amount of fuel required to move a vehicle over a given distance. ...

• The amount of fuel used per unit distance; for example, litres per 100 kilometres (L/100 km). In this case, the lower the value, the more economic a vehicle is (the less fuel it needs to travel a certain distance);
• The distance travelled per unit volume of fuel used; for example, kilometres per litre (km/L) or miles per gallon (mpg). In this case, the higher the value, the more economic a vehicle is (the more distance it can travel with a certain volume of fuel).

Converting from mpg or km/L to L/100 km (or vice versa) involves the use of the reciprocal function, which is not distributive. Therefore, the average of two fuel economy numbers gives different values if those units are used. If two people calculate the fuel economy average of two groups of cars with different units, the group with better fuel economy may be one or the other. The litre or liter (see spelling differences) is a unit of volume. ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... A mile is any of a number of units of distance, each in the magnitude of 1–10 km. ... The gallon (abbreviation: gal) is an English unit of volume. ... In mathematics, the reciprocal, or multiplicative inverse, of a number x is the number which, when multiplied by x, yields 1. ... In mathematics, and in particular in abstract algebra, distributivity is a property of binary operations that generalises the distributive law from elementary algebra. ...

In Europe, the two standard measuring cycles for "L/100 km" value are motorway travel at 90 km/h and rush hour city traffic. A reasonably modern European supermini may manage motorway travel at 5 L/100 km (47 mpg US) or 6.5 L/100 km in city traffic (36 mpg US), with carbon dioxide emissions of around 140 g/km. Motorway mark in Europe. ... 1996 Volkswagen Polo, a popular modern European supermini A supermini is a European hatchback car category. ... Motorway mark in Europe. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ...

An average North American mid-size car travels 27 mpg (US) (9 L/100 km) highway, 21 mpg (US) (11 L/100 km) city; a full-size SUV usually travels 13 mpg (US) (18 L/100 km) city and 16 mpg (US) (15 L/100 km) highway. Pickup trucks vary considerably; whereas a 4 cylinder-engined light pickup can achieve 28 mpg (8 L/100 km), a V8 full-size pickup with extended cabin only travels 13 mpg (US) (18 L/100 km) city and 15 mpg (US) (15 L/100 km) highway. An interesting example of fuel economy is the popular microcar Smart ForTwo, which can achieve up to 4.0 L/100 km (70.6 mpg) using a turbocharged three-cylinder engine. The Smart is produced by DaimlerChrysler and is currently only sold by one company in the United States (see external link ZAP). World map showing North America A satellite composite image of North America. ... A mid-size car, frequently referred to as an intermediate, is an automobile with a size between that of a compact and a full-size or standard-size car. ... // Defenition 2001 E38 Dinan BMW 750iL A full-size car is term used in North America for an automobile larger than a mid-size car, usually having a wheelbase greater than 2. ... A sport utility vehicle (SUV) or off-roader is a vehicle that combines the load-hauling and passenger-carrying capacity of a large station wagon or minivan with features designed for off-road driving. ... Mazda compact Pickup truck with extended cabin and homebuilt lumber rack. ... The Liberty V8 aircraft engine clearly shows the configuration A V8 engine is a V engine with eight cylinders. ... This Smart car is an example of a microcar A microcar is an extremely small automobile. ... Smart (short for Swatch Mercedes ART, sometimes called the MCC Smart) is a brand of microcar based in Böblingen, (Germany). ... Air foil bearing-supported turbocharger cutaway made by Mohawk Innovative Technology Inc. ... DaimlerChrysler AG headquartered in Stuttgart, Baden-Württemberg and Auburn Hills, Michigan, is a prominent automobile and truck manufacturer and financial services provider (through DaimlerChrysler Financial Services). ...

Diesel engines often achieve greater fuel efficiency than petrol (gasoline) engines: 50% of all cars sold in the EU are now diesel vehicles. This can also be attributed to the fact that diesel has 17.6% more energy per unit volume than petrol, and due to economic factors in certain areas, offers more energy for the money.

Fuel efficiency in microgravity

The energy output derived from fuel occurs during combustion. Ensuring a total, even combustion of fuel, as well as harnessable combustion at the appropriate moments, will have an impact on fuel effciency. Recent research by the National Aeronautics and Space Administration (NASA) has gained possible insights to increasing fuel efficiency if fuel consumption takes place in microgravity. This probably does not apply to vehicles so much as industry where the benefit from the increased fuel efficiency will outweigh the initial cost of operating in a microgravity environment. NASA Logo Listen to this article · (info) This audio file was created from the revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Astronauts on the International Space Station display an example of weightlessness Weightlessness is the experience (by people and objects) during freefall, of having no weight. ...

The common distribution of a flame under normal gravity conditions depends on convection, as soot tends to rise to the top of a general flame, such as in a candle in normal gravity conditions, making it yellow. In microgravity or zero gravity, such as an environment in outer space, convection no longer occurs, and the flame becomes spherical, with a tendency to become more blue and more efficient. There are several possible explanations for this difference, of which the most likely one given is that the cause is the hypothesis that the temperature is evenly distributed enough that soot is not formed and complete combustion occurs. ^[1] Experiments by NASA in microgravity reveal that diffusion flames in microgravity allow more soot to be completely oxidised after they are produced than diffusion flames on Earth, because of a series of mechanisms that behaved differently in microgravity when compared to normal gravity conditions. ^[2] Premixed flames in microgravity burn at a much slower rate and more efficiently than even a candle on Earth, and last much longer. ^[3] Convection is the transfer of heat by currents within a fluid. ... Astronauts on the International Space Station display an example of weightlessness Weightlessness is the experience (by people and objects) during freefall, of having no weight. ... Layers of Atmosphere - not to scale (NOAA) Outer space, also called just space, refers to the relatively empty regions of the Universe outside the atmospheres of celestial bodies. ... A sphere (< Greek σφαίρα) is a perfectly symmetrical geometrical object. ... A nearly-turbulent diffusion flame. ... The bright conical flames near the jets of a standard household gas stove are the premixed flame front. ...

Fuel efficiency in transportation

• Humans (see Human-powered transport):
  • walking or running one kilometre requires approximately 70 kcal or 330 kJ of food energy ^[4]. This equates to about 1 l/100km or 235 mpg in gasoline energy terms.
  • cycling requires about 120 kJ/km ^[4]
• Airplanes: passenger airplanes averaged 4.8 l/100km per passenger (1.4 MJ/passenger-km) (49 passenger-miles per gallon) in 1998. Efficiencies around 3 l/100km per passenger are reached by some carriers ^[5]. Note that on average 20% of seats are left unoccupied.
• Ships: the RMS Queen Elizabeth 2 gets 49.5 feet per gallon ^[6] (25,000 l/100km or 13 l/100km per passenger (3.8 MJ/passenger-km)). Note that about 40% of the power produced by the ship engines is used for propulsion, the rest being used to generate electricity for heating, lighting, and other passenger comforts.
• Trains:
  • Freight: the AAR claims an energy efficiency of over 400 ton-miles per gallon of diesel fuel in 2004^[7] (0.588 l/100km per tonne or 235 J/km-kg)
  • Passengers: the East Japan Railway Company claims for 2004 an efficency of 20.6 MJ/car-km, or about 0.35 MJ/passenger-km^[8]

• the Center for Transportation Analysis of the DOE claims the following average figures for the U.S.A. in 2002 ^[9]:

• Rockets:
  • The NASA space shuttle consumes 1,000,000 kg of solid fuel and 2,000,000 litres of liquid fuel over 8.5 minutes to take the 100,000 kg vehicle (including the 25,000 kg payload) to an altitude of 111 km and an orbital speed of 30,000 km/h. This amounts to about 3,300 GJoules of energy, or about 100,000 l/100km or 12 feet per gallon of gasoline. It's worth noting that a rocket can, in theory, re-entry on any place on Earth, giving it a best-case "ground" distance of 20,000 km. This would amount to 500 l/100km or about 0.5 mpg.

This article or section does not cite its references or sources. ... The Space Shuttle Columbia seconds after engine ignition, 1981 (NASA). ... The joule (symbol: J) is the SI unit of energy, or work with base units of kg·m²/s² (N·m). ...

See also

• Emission standard
• Fuel economy in automobiles

Emission standards are requirements that set specific limits to the amount of pollutants that can be released into the environment. ... Fuel economy is the amount of fuel required to move a vehicle over a given distance. ...

References

1. ^ CFM-1 experiment results, National Aeronautics and Space Administration, April 2005.
2. ^ LSP-1 experiment results, National Aeronautics and Space Administration, April 2005.
3. ^ SOFBAL-2 experiment results, National Aeronautics and Space Administration, April 2005.
4. ^ ^a b [1]
5. ^ IATA - Fuel efficiency, IATA
6. ^ [2], Cunard Line
7. ^ Railroads: Building a Cleaner Environment, Association of American Railroads
8. ^ Environmental Goals and Results, JR-East Sustainability Report 2005
9. ^ Passenger Travel and Energy Use, 2002, Center for Transportation Analysis, Oak Ridge National Laboratory