Compression Ratio 10.6: Should I Use 92 or 95 Octane Gasoline?

[DelRosalie]

An engine with a compression ratio of 10.6 requires 95 octane gasoline. Generally, vehicles with engine compression ratios between 8.5-9.5 should use 92 octane gasoline, while those with compression ratios exceeding 9.5 should use 95 octane gasoline. The following explains compression ratio: Definition of Compression Ratio: It refers to the ratio between the total cylinder volume (i.e., working volume plus combustion chamber volume) and the combustion chamber volume. Compression ratio is a crucial structural parameter of an engine, representing the ratio of gas volume when the piston starts compression at bottom dead center to when compression ends at top dead center. Relationship Between Compression Ratio and Gasoline Octane Rating: Generally, higher compression ratio engines compress the air-fuel mixture into a smaller volume, delivering stronger power and lower fuel consumption. However, high compression ratios require another key parameter - the gasoline's anti-knock index (also called octane rating). Higher compression ratio engines demand gasoline with higher anti-knock properties, meaning higher octane ratings.