What happens to the air-fuel mixture during the compression stroke?

During the compression stroke of an internal combustion engine, the air-fuel mixture is drawn into the cylinder during the intake stroke and is then compressed greatly by the upward movement of the piston. This compression serves several critical purposes: it increases the temperature of the mixture, which enhances combustion efficiency, and it ensures that the air-fuel mixture is densely packed, allowing for a more powerful explosion when the spark plug ignites it.

The act of compressing the mixture also contributes to a more complete and efficient burn during the power stroke that follows, thereby maximizing engine performance and minimizing emissions. The increase in pressure and temperature facilitates better combustion, resulting in a more efficient engine operation.

Understanding the dynamics of the compression stroke is crucial for diagnosing engine performance issues and optimizing engine design.