Compression Ratio 10:1 - Should I Use 92 or 95 Octane?

[MacAlan]

For an engine with a compression ratio of 10:1, 95 octane gasoline should be used. Generally, intermediate sedans with compression ratios between 8.5 and 9.5 should use 92 octane gasoline, while sedans with compression ratios above 9.5 should use 95 octane gasoline. Using lower octane gasoline in high compression ratio engines may cause a sharp increase in cylinder temperature and incomplete fuel combustion. Below is more information about engine compression ratio: 1. Engine compression ratio refers to the degree of compression of the engine's air-fuel mixture, calculated as the ratio of the total cylinder volume before compression to the cylinder volume after compression (i.e., combustion chamber volume). 2. Compression ratio is a very important structural parameter of an engine, representing the ratio of the gas volume when the piston is at bottom dead center (start of compression) to the gas volume when the piston is at top dead center (end of compression). 3. From the perspectives of power and fuel economy, a higher compression ratio is generally better. Higher compression ratios provide better power performance and thermal efficiency, improving vehicle acceleration and top speed accordingly. However, constrained by cylinder material properties and gasoline combustion knock, the compression ratio of gasoline engines cannot be too high.