Can 98 and 95 be mixed?
2 Answers
Strictly speaking, 95-octane gasoline and 98-octane gasoline should not be mixed. However, since their chemical compositions and other aspects are relatively similar, and they both have strong anti-knock properties, mixing them generally won't cause significant issues. Nevertheless, it is still best to use them separately. Here is some relevant information about 95-octane and 98-octane gasoline: 1. 95-octane gasoline: 95-octane gasoline is a mixture of 95% isooctane and 5% n-heptane. High-octane gasoline should be used in engines with high compression ratios. Using low-octane gasoline in high-compression engines can lead to abnormal combustion, causing knocking, increased fuel consumption, and reduced driving power. 2. 98-octane gasoline: 98-octane gasoline is a mixture of 98% isooctane and 2% n-heptane. The advantages of 98-octane gasoline are summarized as 'two highs and two lows': higher anti-knock properties and power performance, and lower harmful substances in the gasoline and lower exhaust pollution.
I've been driving for over a decade and often get asked about mixing gasoline grades. Occasionally mixing 98 and 95 octane is fine - once when I was in mountainous areas without 98-octane fuel, I filled up with 95 and drove normally. They have different octane ratings, so mixing them creates blended gasoline with altered anti-knock properties. But don't make it a habit - older cars may accumulate carbon deposits from frequent mixing, and direct injection engines have more sensitive fuel injectors. If you're worried about running out of fuel on long trips, after mixing grades quickly add a bottle of fuel additive and burn through the tank before switching back to a single grade. However, it's best not to try this with high compression ratio engines - my neighbor's turbocharged car once triggered the check engine light after mixing fuels.
