Hybrid-electric vehicles (HEVs) combine the benefits of gasoline engines and electric motors and can be configured to obtain different objectives, such as improved fuel economy or increased power.  Some of the advanced technologies typically used by hybrids include regenerative braking, electric motor drive/assist, and automatic start/shutoff.

Diesel engines are more powerful and fuel-efficient than similar-sized gasoline engines (about 30-35% more fuel efficient). Improved fuel injection and electronic engine control technologies have increased power, improved acceleration and increased efficiency. New "clean" diesel fuels, such as ultra-low sulfur diesel and biodiesel reduce emissions that cause pollution.

Flexible fuel vehicles (FFVs) are designed to run on gasoline or a blend of up to 85% ethanol (E85). Except for a few engine and fuel system modifications, they are identical to gasoline-only models. Ethanol is produced domestically from corn and other crops and produces less greenhouse gas emissions than conventional fuels.