A hybrid electric vehicle contains an electric engine which allows a smaller and more efficient combustion engine to be used. Hybrids emit fewer tailpipe pollutants than vehicles with traditional combustion engines, and they use less fuel.

An electric vehicle uses an electric engine powered by a rechargeable battery pack. While electric vehicles often use electricity that is generated by burning coal and other fossil fuels, they do not emit tailpipe pollutants, and they have the potential to run on electricity generated by renewable sources, such as solar, wind, and geothermal.

Other alternatives to traditional gasoline fuel include: diesel, biofuel, liquefied petroleum gas (LPG), compressed natural gas, and hydrogen fuel cells (still in developmental stages).

Click for more information on efficient and alternative fuel vehicles, fuel economy and labeling, and the carbon footprints of different vehicle types.