Can a car that uses 98 octane fuel use 95 octane fuel?
2 Answers
You can add 95 octane fuel after using 98 octane fuel, but it is not recommended to do so long-term. Please note the following: 1. Do not mix different octane ratings of gasoline. If you previously used 98 octane fuel, you should continue to use 98 octane fuel for the next refueling. 2. In special circumstances, adding 95 octane fuel once is not a major issue, but prolonged use can lead to engine knocking, increased carbon deposits, and higher fuel consumption. 3. Similarly, if a car owner has been using 95 octane fuel, adding 98 octane fuel once or twice will not have a significant impact, but long-term mixing is not advisable. 4. If a car owner wishes to switch gasoline octane ratings, it is best to wait until the fuel tank is nearly empty (when the fuel gauge light comes on) before refueling with the new octane rating, or to drain the remaining fuel before switching, rather than mixing the two directly.
As someone who frequently drives sports cars, I know that 98-octane fuel is designed for high-octane requirements to prevent engine knocking. Using 95-octane fuel may cause the engine to 'ping,' and knocking can damage pistons and cylinders. In mild cases, it leads to reduced power and slower acceleration; in severe cases, it increases carbon buildup and doubles maintenance costs. Although modern car ECUs can adjust ignition timing to mitigate the issue, long-term mixing of fuels carries significant risks, especially during high-load, long-distance driving in summer. Always follow the manual's recommendation to use 98-octane fuel. Only use 95-octane in emergencies when 98 is unavailable—never save small money at the risk of major repairs. For the car's longevity, using the right fuel ensures smoother, more stable performance and slightly better fuel efficiency. Remember, knocking sounds like metal tapping—if you hear it, address it immediately.
