Can I add 95 gasoline when there is still 92 gasoline in the car?
2 Answers
Yes, you can. Here is an introduction about gasoline: 1. Gasoline grade: The higher the gasoline grade, the stronger its anti-knock performance, which has nothing to do with the quality of the gasoline. Gasoline and air are mixed and compressed in the cylinder. If the pressure is too high, detonation may occur, causing the engine to malfunction. In fuel, the anti-knock substance is isooctane. 2. Gasoline anti-knock performance: The higher the grade, the higher the isooctane content and the stronger the anti-knock performance. Therefore, whether it is 92 gasoline or 95 gasoline, they only differ in the content of isooctane in the gasoline. The quality of the gasoline and the calorific value per unit volume of fuel are the same.
I've always used 92-octane fuel in my car. Once when there was still half a tank of 92 left, I directly topped it up with 95-octane. It drove fine with no noticeable issues—the engine ran smoothly without any knocking sounds, and fuel consumption even decreased slightly. Car manufacturers generally say mixing fuel grades is safe unless your vehicle specifically requires high-octane fuel, in which case you shouldn’t mix randomly. I usually recommend checking the owner’s manual to confirm the recommended fuel type—no need to worry too much. My old Toyota runs just fine this way. Of course, long-term fuel mixing might lead to slightly more carbon buildup, so periodic fuel injector cleaning would help. Safety first—always check the fuel pressure gauge before driving for extra peace of mind.
