The Basics of Cars

The Engine The engine burns a mixture of fuel, like gasoline or diesel, and air in a controlled way to create energy. This energy is then used to move parts of the engine, which ultimately powers the car's wheels. Most car engines operate using a four-stroke cycle. It starts with the intake valve opening, and a piston moving down. This creates a vacuum, which pulls in a mixture of air and fuel into the combustion chamber. The intake valve closes, and the piston moves up. This compresses the air-fuel mixture, making it more explosive. A spark plug ignites the compressed air-fuel mixture and the explosion forces the piston down, creating mechanical energy. The exhaust valve opens, and the piston moves up again. This pushes out the burned or exhaust gases through the exhaust system. The number of pistons determines a car's torque, though it also depends on the kind of car. The Crankshaft converts the pistons' up-and-down motion into rotational motion to power the wheels. Th...