Can 92 and 95 Octane Gasoline Be Mixed?
2 Answers
92 and 95 octane gasoline can be mixed. The composition of 95 octane gasoline is the same as that of 92 octane, with 95 octane being more stable. The quality of both types of gasoline is identical; the only difference lies in the amount of anti-knock agent added. Each engine has a different compression ratio, and the recommended gasoline grade can be found on the inside of the fuel tank cap. Vehicles with a compression ratio between 8.5 and 9.5 should use 92 octane gasoline, while those with a compression ratio greater than 9.5 should use 95 octane gasoline. Engines with higher compression ratios have greater power and fuel efficiency but lower stability, hence requiring gasoline with better anti-knock properties. The advantage of 95 octane gasoline over 92 octane lies in its higher proportion of octane in the gasoline, which provides better anti-knock performance.
My own car is a regular family sedan, and the manual says 92-octane fuel is sufficient. Once when the gas station ran out of 92-octane, I had to mix in some 95-octane, and it ran perfectly fine with smooth acceleration and steady engine noise. Talking to my mechanic friend, he said modern car ignition systems are quite smart and can automatically adapt to different fuel octane ratings—mixing them temporarily isn’t a big issue. However, long-term mixing might slightly reduce fuel efficiency or cause more spark plug deposits, so it’s best to stick to the manual’s recommendation for regular use. For emergencies, especially during long trips when the right fuel isn’t available, it’s completely fine.
