A hybrid car uses two types of propulsion at once, combining a petrol or diesel engine with an electric motor. Conventional hybrid vehicles are designed to allow the engine to generate power to charge the electric motor. Plug-in versions have larger batteries that can be charged via a wall socket or charging point, and can run for longer distances on electric power alone than standard hybrids.
In conventional hybrid vehicles, the electric motor drives the car at low speeds and works in tandem with the engine when maximum acceleration is applied. The car recycles the excess energy by using it to charge the electric motor, occurring for example when you brake. This ensures that the hybrid’s engine does less work than normal combustion-powered versions.
Hybrid vehicles provide great fuel economy, as the electric motor combines with the engine when the car accelerates to support the strain. This support from the electric motor also allows for a smaller and more economical engine to be fitted, which means less fuel is expended as you drive.
As you'd expect from a car that provides an electric motor to offset the work that its engine has to do, hybrid vehicles release less CO2 into the environment. Hybrids emit an average of 75g/km of CO2, while fully-electric versions generate zero emissions.
Plug-in hybrid vehicles occupy a midway point between conventional hybrid vehicles and electric models. They have larger batteries than standard hybrids, meaning they can run for longer distances on electric power alone and can be recharged at outlets while on the move.