Hybrids save money and cut emissions by boosting fuel efficiency.
Hybrid electric vehicles (HEVs) are powered by an internal combustion engine combined with a battery-powered electric motor. HEVs run on gasoline and don’t need to be plugged in to recharge the battery. Because HEVs travel at least part of the time on battery power alone, they require fewer fill-ups and are more economical to run. Some HEVs achieve fuel economy of 40 to 50 miles per gallon. They also produce lower levels of tailpipe and GHG emissions than conventional vehicles.
Light-duty HEVs are parallel hybrids meaning both the engine and electric motor are mechanically connected to the wheels, and either or both can propel the vehicle directly, depending on the power requirements and battery charge.
Hybrid configuration affects performance and price.
HEVs can be either mild or full hybrids. Full hybrids can run on battery power alone at idle or low speeds. When speeds increase, the gasoline engine works with the electric motor to provide power. Full hybrids are 25% to 40% more fuel efficient than comparable conventional vehicles.
Mild hybrids, also called “micro hybrids”, use a battery and electric motor to help power the vehicle. This allows the engine to shut off when the vehicle stops at traffic signals and in stop-and-go traffic, thus improving fuel economy. Mild hybrids cannot power the vehicle using electricity alone. These vehicles cost less than full hybrids, but they provide lower fuel economy.