Can I add 95 octane gasoline after using 92 octane?
2 Answers
It is possible to add 95 octane gasoline after using 92 octane. The gasoline octane rating represents the fuel's octane number. For example, 92 octane gasoline consists of approximately 92% isooctane and about 8% n-heptane. Since isooctane has better anti-knock properties while n-heptane has poorer anti-knock characteristics, a higher octane rating indicates better anti-knock performance of the gasoline. Manufacturers typically specify the recommended or minimum required gasoline octane rating on the inside of the fuel filler door, such as "Use 92 octane or higher". Here, 92 octane represents the minimum standard gasoline specification, but this doesn't necessarily mean it's the optimal fuel for achieving the best fuel efficiency ratio.
I've driven for several years and encountered this situation before. I think adding 95 octane gasoline after filling up with 92 octane is generally not a big problem, but it depends on the specific vehicle. My friend drives a Hyundai Sonata, and he said mixing the two grades twice didn't make much noticeable difference, but long-term use could lead to carbon buildup or affect engine performance. Car engines are designed with some tolerance, and modern vehicle computers can slightly adapt to different octane ratings, but it's best not to mix them frequently. I suggest sticking to one octane rating the next time you go to the gas station to avoid trouble. Additionally, mixing gasoline may sometimes cause a slight increase in fuel consumption or reduced power sensation, especially in older cars or high-compression ratio models. In short, don't worry too much if you encounter this situation, but try to follow the manual's recommended octane rating in the future to protect your engine and have peace of mind.
