In terms of engine operation, which type typically requires a higher compression ratio?

The diesel engine typically requires a higher compression ratio compared to other engine types, which is why this choice is the correct one. Diesel engines operate on the principle of compression ignition, meaning that the air within the combustion chamber is compressed to a much greater extent than in gasoline engines. This higher compression raises the temperature of the air to a point where fuel can ignite without the need for a spark plug, which is characteristic of gasoline engines.

The high compression ratio in diesel engines allows for increased thermal efficiency, leading to better fuel economy and more power output from a smaller displacement engine. In contrast, gasoline engines generally operate at lower compression ratios, primarily to prevent knocking or pre-ignition, which can damage the engine.

Electric engines do not operate on the concept of combustion and therefore do not have a compression ratio related to their function. Hybrid engines, which combine both electric and gasoline or diesel power, inherit the characteristics of their gasoline or diesel components but do not have a standalone compression ratio in the same context as purely gasoline or diesel engines. This unique operational mechanism reinforces why the diesel engine requires a higher compression ratio.