What is an internal combustion engine (ICE)?

Until the recent growth of electric vehicles, all cars were powered by internal combustion engines. These create wheel-turning power by burning petrol, diesel or LPG (liquefied petroleum gas) – using broadly the same fundamental design for more than one hundred years. Engines are described as 'internal combustion' because they combust (burn) fuel internally within their cylinders to generate kinetic energy.

Internal combustion engines are great for long-distance driving because they have fuel tanks that can be rapidly refilled at any petrol station. They have several drawbacks compared with electric motors, however, including being noisier and more complex, and they emit harmful greenhouse gases in their exhaust emissions that cause environmental damage.