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How does a car engine work?

An internal combustion engineMost cars are driven by engines fuelled by petrol or diesel. These engines are called internal combustion engines. The engine supplies power to turn the wheels. The driver can go faster by pressing the accelerator (or gas) pedal. This increases the flow of fuel to the engine. Gears allow the car to be driven at different speeds without the engine running too slowly or too quickly.


Petrol engine

A cutaway illustration of an internal combustion engine Movement of a piston inside a cylinder. KEY: 1. Petrol is drawn into the cylinder 2. The petrol-air mixture is squeezed or...Read More >>Movement of a piston inside a cylinder. KEY: 1. Petrol is drawn into the cylinder 2. The petrol-air mixture is squeezed or compressed. 3. The petrol-air mixture is ignited, forcing the piston down. 4. Waste gases are pushed out.Petrol is drawn from the fuel tank into the engine and sprayed into its cylinders, mixing with air. The petrol-air mixture is ignited by spark plugs, setting off mini-explosions. The hot gases produced force pistons inside the cylinders down.

A hybrid electric vehicle (HEV) combines an internal combustion engine with batteries that power an electric motor. When the batteries run down, the petrol or diesel engine switches on and recharges them.

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