Editing Hybrid vehicle (section)

===Power-split or series-parallel hybrid===
In a power-split hybrid electric drive train, there are two motors: a traction electric motor and an internal combustion engine. The power from these two motors can be shared to drive the wheels via a power split device, which is a simple [[epicyclic gearing|planetary gear]] set. The ratio can be from 100% for the combustion engine to 100% for the traction electric motor, or anything in between. The combustion engine can act as a generator charging the batteries.

Modern versions such as the Toyota [[Hybrid Synergy Drive]] have a second electric motor/generator connected to the planetary gear. In cooperation with the traction motor/generator and the power-split device, this provides a continuously variable transmission.

On the open road, the primary power source is the internal combustion engine. When maximum power is required, for example, to overtake, the traction electric motor is used to assist. This increases the available power for a short period, giving the effect of having a larger engine than actually installed. In most applications, the combustion engine is switched off when the car is slow or stationary thereby reducing curbside emissions.

Passenger car installations include [[Toyota Prius]], Ford Escape and Fusion, as well as [[Lexus RX]]400h, RX450h, GS450h, LS600h, and CT200h.