Can 95 and 92 be mixed?
2 Answers
Strictly speaking, 92-octane gasoline and 95-octane gasoline should not be mixed. Below are the differences between 92-octane and 95-octane gasoline: In terms of n-heptane content: 95-octane gasoline contains 5% n-heptane; 92-octane gasoline contains 8% n-heptane. In terms of isooctane content: 95-octane gasoline contains 95% isooctane; 92-octane gasoline contains 92% isooctane. In terms of anti-knock properties: Different gasoline grades represent different fuel anti-knock properties. The higher the gasoline grade, the better the anti-knock properties. 95-octane gasoline has better anti-knock properties than 92-octane gasoline.
I've been driving for over ten years, and occasionally mixing 92 and 95 octane gasoline isn't really a big deal. Once when I was on a business trip and the gas station only had 92 octane, I added half a tank to my 95 octane tank, and the car still ran just fine. The key is the engine's compression ratio—ordinary family cars' computers automatically adjust the ignition timing to prevent knocking. However, long-term mixing might increase carbon deposits and slightly raise fuel consumption. It's best not to make it a habit, especially for turbocharged models—stick to the manufacturer's recommended octane rating. For long trips, carrying a bottle of fuel additive as a preventive measure is a safer bet.
