How does a diesel engine differ from a gasoline engine regarding ignition?

A diesel engine operates using the principle of compression ignition. In this process, air is compressed to a high degree, resulting in a significant increase in temperature. Once the air is sufficiently heated, fuel is injected into the combustion chamber. The high temperature of the compressed air ignites the diesel fuel without the need for a spark plug.

This method of ignition differentiates diesel engines from gasoline engines, which primarily use spark ignition. In gasoline engines, the air-fuel mixture is compressed to a lower extent than in diesel engines and requires a spark from a spark plug to ignite the fuel.

Understanding this distinction is crucial for diagnosing issues and servicing diesel engines effectively. It highlights the different combustion processes and fuel types used in these engines, which ultimately impact their operation, efficiency, and maintenance requirements.