What burns in an internal combustion engine of a car?

In the internal combustion engine of a car, a mixture of air and fuel (usually gasoline) is burned to produce power. This combustion process takes place within the engine's cylinders, where a piston moves up and down to convert the energy released from the burning fuel into mechanical motion. Here's a simplified explanation of what burns in an internal combustion engine:

1. Air and Fuel Mixture: Before combustion can occur, a mixture of air and fuel must be created. The air is drawn into the engine through an air intake, and the fuel is injected or mixed with the air. This mixture is then compressed by the piston as it moves upwards in the cylinder.

2. Compression: The compression of the air-fuel mixture increases its pressure and temperature. This compression is crucial because it helps to create a more efficient and controlled combustion process.

3. Ignition: At the top of the compression stroke, just before the piston reaches its highest point, a spark plug generates an electric spark. This spark ignites the compressed air-fuel mixture, causing it to burn rapidly and expand.

4. Combustion: The rapid burning of the air-fuel mixture creates a high-pressure force inside the cylinder. This force pushes the piston down, generating power. The expanding gases also create heat and pressure, which are essential for the engine to function.

5. Exhaust: After the combustion process, the burnt gases (exhaust) need to be expelled from the cylinder. The exhaust valve opens, and the piston moves upwards, pushing the exhaust gases out through the exhaust system.

This cycle of intake, compression, combustion, and exhaust repeats continuously as the engine operates. The controlled burning of the air-fuel mixture inside the cylinders generates the power that drives the vehicle.