Quite simply, a hybrid car is one that uses more than one means of propulsion. At the moment, that exclusively means combining a conventional internal combustion engine with an electric motor.
The chief advantages of a hybrid are that it uses less fuel and emits less CO2 than a conventional non-hybrid vehicle.
On top of that, there can be further benefits, in the shape of lower rates of road- and company car tax, as well as possibly avoiding congestion charges.
How they work In every current hybrid, the internal combustion engine is petrol-powered, but diesel hybrids are planned. The first to go on sale is expected to be a diesel-hybrid version of the Peugeot 3008 crossover.
That will be a unique model, but even now it’s almost true to say that no two hybrids are exactly the same.
In the Toyota Prius, for example, each of the power sources can drive the car separately or they can work together.
At low speeds, the engine is turned off and the car is driven only by the electric motor; then, when maximum acceleration is needed, both work together. At stages between, any excess power generated by the engine is used to recharge the batteries that power the electric motor.
The Honda Insight, on the other hand – probably the second-most well-known hybrid in the UK – is slightly different. Here, a relatively small conventional engine uses an electric motor to give it extra help when required. Although the car does incorporate a stop-start system, it can never be driven by only the electric motor.
Plug-in hybrids Then, there are the so-called ‘plug-in hybrids’, which – as the name implies – can be plugged into an electric outlet to recharge their batteries, as well as being charged on the move.
Effectively, they are a halfway house between conventional hybrids and full electric vehicles. Although they have a conventional engine, they also have larger batteries than regular hybrids and can drive longer distances on electric power alone.
The plug-in hybrid version of Toyota’s Prius, for example, uses lithium-ion batteries and can be driven over short distances – and at speeds of up to 60mph – on battery power alone. When the batteries run low, the car runs as a conventional hybrid.
You may also hear of a ‘mild hybrid drive’, such as Smart uses on its Fortwo. However, this is not strictly a hybrid, because there is only one power source. Instead, it simply uses a stop-start system to turn off the engine when it’s not needed.