Is 98 Octane Gasoline More Fuel-Efficient Than 95 Octane?
2 Answers
We only need to refuel according to the vehicle's factory manual, rather than deliberately upgrading the gasoline grade. 92, 95, and 98 octane ratings are just gasoline grades, representing anti-knock performance. The higher the octane number, the better the anti-knock performance, but it has nothing to do with the quality of the gasoline itself. A higher octane number does not mean fewer impurities in the gasoline. They are the same in terms of quality and cleanliness. The biggest difference between them lies in the octane value. 98 octane gasoline contains a slightly higher proportion of anti-knock additives compared to 95 and 92 octane gasoline, but the quality is exactly the same, and it has nothing to do with cleanliness. As for the different amounts of anti-knock additives, it is to meet the different requirements of engines with different compression ratios for anti-knock values. Therefore, gasoline with a higher octane value should be used to avoid knocking. If low-octane gasoline is added, the engine will knock, resulting in reduced power and increased fuel consumption. If the car manual states "minimum 92 octane gasoline," then gasoline below 92 octane cannot be used. If the manual states a minimum of 95 octane gasoline, then gasoline below 95 octane cannot be used.
I've driven over a dozen types of cars, ranging from old Santanas to new SUVs. I remember conducting a specific test where I ran the same highway route with 98 and 95 octane fuel respectively, and the difference was negligible—only about 0.1 liters saved per 100 kilometers. In fact, the fuel octane rating mainly reflects anti-knock performance and has little to do with fuel efficiency. 98 octane performs more stably in turbocharged cars; for example, in my turbocharged vehicle, reduced engine knocking results in quicker throttle response. However, using 98 octane in a naturally aspirated engine is just a waste, as the money is spent on additives. Driving habits have a greater impact on fuel consumption—my friend, who always accelerates aggressively from a standstill, burns through 98 octane just as quickly. I recommend prioritizing the recommended fuel grade indicated on the fuel cap, as matching the engine's requirements is the most practical approach.
