Hybrid vehicles combine two familiar technologies: gasoline engines and electric motors. When they are used together, it's an entirely new paradigm. The resulting synergy achieves better results with two kinds of power than is possible by using either one alone.

For example, the electric motor adds extra power during peak demands, enabling the use of a smaller, lighter and less polluting engine. The gasoline engine provides most of the power. It recharges the hybrid battery for hundreds of miles of range, so today's hybrids don't plug into rechargers. The batteries also get energy back from the drivetrain in a process called regenerative braking. Imagine-a vehicle that recycles its own energy!

Full hybrids-the most advanced
Hybrid powertrains differ in motor and engine combinations. The "full hybrid" is generally the most advanced type. Full hybrids run on electric drive at low speeds, on gasoline and electric drive in traffic, and on gasoline alone at highway speeds. Computers automatically control the electric motor and gasoline engine for an optimal balance of responsive performance, fuel economy and lower emissions. This is synergy in action.

Power-assist hybrids
The power-assist hybrid, sometimes called the "mild hybrid," relies on the engine to power the vehicle at all times. In this type of hybrid, the electric motor assists the engine as needed for greater efficiency and lower emissions. Motors and batteries are less powerful than in full hybrids. The transmission can be automatic or manual, and is largely the same as in a conventional car. As with full hybrids, power-assist hybrids have regenerative braking.

Low-voltage hybrids
Full-size pickup trucks are entering the market with low-voltage hybrid components. Gas mileage may improve by about 12%. An "integrated starter-generator" (ISG)-a motor between the engine and transmission-replaces the conventional alternator and starter. ISGs can have limited power boost and regenerative capability. They also enable engine shutoff when the vehicle stops in traffic, for improved mileage and lower emissions.

Keeping the lead in hybrid technology
Toyota holds more than 300 key patents pertaining to hybrid drivetrains and shares hybrid technology, licensing cleaner vehicle technology to companies that request it. This approach will support the acceptance of all hybrid vehicles, and has the potential to make Hybrid Synergy Drive® the most widely used hybrid standard in the industry.