Which type of engine typically has a higher range in compression ratio?

Diesel engines typically have a higher range in compression ratio compared to other types of engines. This is due to the fundamental design and operational principles of diesel engines, which rely on compression ignition.

In a diesel engine, air is compressed to a much greater extent during the intake and compression strokes, resulting in very high pressure and temperature. The combustion process is initiated by injecting fuel into this highly compressed air, leading to more efficient fuel combustion. These characteristics allow diesel engines to achieve compression ratios often ranging from about 14:1 to over 25:1.

In contrast, gasoline engines generally operate at lower compression ratios, usually between 8:1 and 12:1, since they use spark plugs for ignition. Electric engines do not rely on combustion and, therefore, do not have a compression ratio relevant to the question, while hybrid engines, which combine gasoline and electric power, typically exhibit compression ratios similar to their gasoline counterparts. This context highlights why diesel engines stand out with their ability to achieve higher compression ratios, enhancing their performance and efficiency.