Fuel Efficiency

Other applications, such as Industry , benefit from increased fuel efficiency, especially Fossil Fuel Power Plant s or industries dealing with combustion, such as Ammonia production during the Haber Process .

ENERGY CONTENT OF FUEL

FUEL EFFICIENCY

cars in Amsterdam are extremely small, not only to save fuel but to occupy less space in expensive parking areas.]]

Fuel efficiency is normally expressed in terms of Power per unit of Engine Displacement , also known as specific output. It should be noted that despite common usage, "fuel efficiency" is not a synonym for "fuel economy" or "gas mileage". Modern Fuel Injected engines are much more efficient at producing power than their Carbureted predecessors. For example, power output from Chrysler 's 3.9 L '' LA '' V6 engine jumped from 125 Hp (93 kW) to 180 hp (134 kW) in 1992 due to the addition of fuel injection and a free-flowing Intake Manifold .

However, improvements in fuel efficiency achieved over the last 20 years have not been translated into improvements in fuel economy — much of the savings have been offset by the use of heavier and less- Aerodynamic body styles (especially SUV s and Pickup Truck s) and the use of more-powerful engines. For example, the 6.0 L '' Vortec '' V8 used in the Hummer H2 produces 53.6 hp (39 kW) per liter of displacement, which is more than double the 25.4 hp (19 kW) per liter produced by the original VW Beetle . However, the Hummer weighs more than four times as much as the original Beetle, has a much less-aerodynamic body, and uses a complex Four Wheel Drive system, so the Beetle is able to travel three times farther than the Hummer on the same amount of fuel.

Naturally aspirated engines tend to be more fuel efficient than engines with forced induction (ex: turbocharged, supercharged).

FUEL ECONOMY

See Also: Fuel economy in automobiles

Fuel economy is usually expressed in one of two ways:

The amount of fuel used per unit distance; for example, Litre s per 100 Kilometre s (L/100 km). In this case, the lower the value, the more economic a vehicle is (the lees 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 Mile s 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.

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.

An average North America n 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 Truck s 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 ).

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 aslo 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.

The common distribution of a flame under normal gravity conditions depends on s in microgravity burn at a much slower rate and more efficiently than even a candle on Earth, and last much longer. SOFBAL-2 experiment results , National Aeronautics and Space Administration, April 2005.

FUEL EFFICIENCY IN TRANSPORTATION

Humans (see Human-powered Transport ):

--- walking or running one kilometre requires approximately 70 energy terms.

--- Cycling requires about 120 kJ/km

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 IATA - Fuel efficiency , IATA . Note that on average 20% of seats are left unoccupied.

Ships: the (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 (0.588 l/100km per tonne or 235 J/km-kg)

--- Passengers: the Sustainability Report 2005

the Center for Transportation Analysis of the DOE claims the following average figures for the U.S.A. in 2002 Passenger Travel and Energy Use, 2002 , Center for Transportation Analysis, Oak Ridge National Laboratory:

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 G Joule s 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.

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Fuel Efficiency