How does compression in a diesel engine affect fuel combustion?

In a diesel engine, compression plays a crucial role in the combustion process. The correct answer highlights that compression increases the ignition temperature of the air-fuel mixture. During the compression stroke, the air in the cylinder is compressed to a much smaller volume, which results in a significant increase in temperature due to the principles of thermodynamics.

This elevated temperature is critical because diesel fuel requires a higher ignition temperature compared to gasoline. As the piston compresses the air, the temperature can exceed the fuel's auto-ignition threshold, allowing the diesel fuel to ignite spontaneously when injected into the highly compressed and heated air. This process is essential for the efficient operation of diesel engines and results in more complete combustion of the fuel, leading to better power output and efficiency regarding fuel utilization.

In summary, the increase in ignition temperature resulting from compression is fundamental to the efficient and effective combustion of diesel fuel, which is why this response is accurate.