Energy info zone
Energy Energy today Energy futures energy action

Infernal combustion engine

The job of an engine is to use the energy stored in fuel to make a vehicle move.

The first self-propelled road vehicle was fitted with a steam engine, which is an external combustion engine. This means that the fuel used to make the steam is burned outside the engine.

The first car to run on petrol was built in 1885 and since then almost all cars have run on petrol.

A petrol engine is an internal combustion engine, which means that the fuel is burned inside the engine. It uses less fuel per mile than an external combustion engine and is also a lot smaller.

To generate motion you burn the petrol inside the engine - if you put a tiny amount of fuel in a small, enclosed space and ignite it, it explodes and energy is released.

Petrol comes from oil. Crude oil is pumped out of the ground and sent to a refinery where it is split into different types of oil, such as petrol and a heavier form of petrol called diesel.

Diesel engines are more efficient and produce less carbon dioxide than petrol engines. But they are noisier and their acceleration isn't as good. Which would you prefer?

What is "Combustion"?
What is "Engine"?
What is "Fuel"?
Fascinating fact
Fascinating fact

First petrol car
First petrol car

Oil fields, California
Oil fields, California

Engines in action
Watch: Engines in action