Technology
How does a car engine work?
A petrol car engine works by burning fuel inside cylinders in tiny, rapid explosions. Each explosion pushes a piston, and those pistons turn a crankshaft that ultimately spins the wheels — repeating the four-stroke cycle thousands of times a minute.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a car engine works.
Step by step
- 1Intake: the piston draws in a mix of air and fuel.
- 2Compression: the piston squeezes that mixture.
- 3Combustion: a spark ignites it, and the explosion forces the piston down (the power stroke).
- 4Exhaust: the piston pushes out the burnt gases, and the cycle repeats.
Frequently asked questions
- What is the four-stroke cycle?
- Intake, compression, combustion, and exhaust — the four piston movements that repeat to produce power.
- How does the engine turn the wheels?
- Pistons turn the crankshaft, which sends power through the transmission to the wheels.
- How is an electric motor different?
- An electric motor uses magnetism and electricity to spin directly — no fuel, combustion, or pistons.