Hybrid cars are vehicles that are partly powered by fossil fuels such as petrol, and partly by electricity (which may be generated on board). The basic idea comes from knowing how to reduce fuel use in the traditional car engine, the internal combustion engine. With an internal combustion engine, we would ideally like to run it at its most efficient speed (called the optimum point meaning its best point) where it uses least fuel. But in a car, we must run the wheels to match the speed of the car. That’s why we have gears (manual or automatic). But even with gears there is still a mismatch. When we drive at a steady speed on the motorway and that speed is close to the engine’s optimum speed then we can find we reduce our fuel use, sometimes impressively so. So, what if we drive our wheels using electric motors and run the internal combustion engine at its optimum point to generate electricity? That’s the idea with a hybrid car. We can significantly reduce petrol use by doing this. It helps to have a small battery to allow us to draw more power when we need it and store charge when we don’t. That was the petrol engine can run steadily and when the battery is full it can simply switch off. We can get lower emissions of carbon dioxide even in a city centre with a hybrid car.

Some hybrid cars have an electric plug and a bigger battery. These are called plug-in hybrid vehicles and can be driven with even lower emissions by making use of more electricity and can be zero emissions over short journeys a bit like an electric car.

Hybrid cars are attractive to some because they combine the long range of a traditional car with lower fuel use and the ability to be zero emission over very short distances. However with the advent of better performing batteries, newer pure electric cars are getting longer ranges.

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