Can 95 and 92 gasoline be mixed?
2 Answers
95 and 92 gasoline can be mixed, as the composition of 95-octane and 92-octane gasoline is the same. 95-octane gasoline is more stable, but the quality of both types of gasoline is identical, and there is no difference in cleanliness or other factors. The only difference lies in the amount of anti-knock agent added, which is designed to meet the varying anti-knock requirements of engines with different compression ratios. Each engine has a specific compression ratio and a recommended gasoline grade, which can usually be found on the inside of the fuel tank cap. Generally, vehicles with a compression ratio between 8.5 and 9.5 are recommended to use 92-octane gasoline, while those with a compression ratio above 9.5 should use 95-octane gasoline. High-compression-ratio engines offer greater power and fuel efficiency but often lack stability, hence requiring gasoline with better anti-knock properties. The advantage of 95-octane gasoline over 92-octane lies in its higher octane value, which provides superior anti-knock performance.
Mixing 92 and 95 octane gasoline occasionally is not a big issue. I often encountered similar situations when helping friends with vehicle maintenance. Mixing gasoline with different octane ratings simply results in an intermediate anti-knock performance. For example, if you usually use 95 octane and mix in 92, it slightly lowers the fuel's anti-knock performance, which older cars or those with low compression ratios can generally adapt to. However, be cautious with turbocharged vehicles or newer direct-injection engines, as mixing fuels might trigger the check engine light. Once, I came across a car that had mixed three different octane grades, and it noticeably lacked power during highway acceleration. It's best not to make a habit of mixing fuels, but doing so occasionally in an emergency is fine—just fill up with the same octane when the tank is less than half full to dilute the mixture.
