Alternative Fuels for Gasoline

With environmental concerns more prevalent than ever--and petroleum reserves in limited supply--consumers and auto manufacturers alike are eagerly searching for alternative fuels for gasoline in motor vehicles. Some of the more noteworthy replacement fuel sources currently being explored include ethanol, biodiesel fuel, natural gas, and hydrogen.

E85 Ethanol

E85, named because it contains as much as 85-percent processed ethanol, is produced domestically. It's produced mostly in the Midwest, from corn and other crops. E85 is very popular in Sweden, though currently fewer than 2,000 filling stations in the U.S. provide ethanol to consumers.

Biodiesel Fuel

A non-petroleum fuel made out of animal fat and vegetable oil, biodiesel is believed to reduce engine wear. A mixture of 20-percent biodiesel and 80-percent petroleum-based diesel can be used in most diesel automobile engines without modification. Nearly four million tons of this fuel type was produced worldwide in 2005, most of it in Europe.

Natural Gas

Compressed natural gas, or CNG as it is known, is made primarily of methane, compressed to power automotive vehicles in place of gasoline or diesel. CNG engines are about as efficient as their gasoline-powered counterparts, though diesel engines typically run more efficiently.

Hydrogen Vehicles

Several automotive manufacturers are currently experimenting with vehicles that run on hydrogen fuel cells. Audi, Chrysler, Fiat, Ford, General Motors, Honda, Hyundai, Mazda, Renault, and Toyota are among the manufacturers that have already successfully produced vehicles that convert hydrogen to mechanical energy, thus powering an electrical motor.

Environmental Benefits of Alternative Fuels

Much of the reason manufacturers are exploring alternative fuels for gasoline is because of the environmental benefits they are either perceived or proven to have. E85 may produce fewer emissions than petroleum-based fuel, though this claim is being challenged. Biodiesel is also supposed to cause less air pollution, while CNG produces fewer greenhouse gases than traditional fuels, and pure hydrogen fuel cells emit no harmful fumes whatsoever.