www.fueleconomy.gov buttonbanner graphic: orange to gray bar
Hybrid button Full Hybrid button highlighted Stop/Start buttonbanner graphic: blue bar
subbanner graphic: gray barOverview Button highlightedStarting buttonLow Speed buttonCruising buttonPassing buttonBraking buttonStopped button

OVERVIEW

Full hybrids use a gasoline engine as the primary source of power, and an electric motor provides additional power when needed.

In addition, full hybrids can use the electric motor as the sole source of propulsion for low-speed, low-acceleration driving, such as in stop-and-go traffic or for backing up.

This electric-only driving mode can further increase fuel efficiency under some driving conditions.
stage graphic: vertical blue rule
Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.
Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.
Battery: The battery stores energy generated from the gasoline engine or, during regenerative braking, from the electric motor. Since the battery powers the vehicle at low speeds, it is larger and holds much more energy than batteries used to start conventional vehicles.Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.
Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.
Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.Gasoline Engine: The gasoline engine in a hybrid is much like those in conventional vehicles, except that it is usually much smaller and more efficient.Generator: The generator converts mechanical energy from the engine to electricity which can be used by the electric motor or stored in the battery. It is also used to start the gasoline engine instantly when needed.
Power Split Device: The power split device is a gearbox connecting the gasoline engine, generator, and electric motor. It allows the engine and motor to power the car independently or in tandem and allows the gasoline engine to charge the batteries or provide power to the wheels as needed. Electric Motor: The electric motor powers the vehicle at low speeds and assists the gasoline engine when additional power is needed. It also converts otherwise wasted energy from braking into electricity and stores it in the battery.
Gasoline Engine: The gasoline engine in a hybrid is much like those in conventional vehicles, except that it is usually much smaller and more efficient.Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.
Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection.
Rollover area: Rollover the hybrid components to get more information
Footer area: Logos for the U.S. Department of Energy, Energy Efficiency and Renewable Energy and the United States Environmental Protection Agency