Can 95 Octane Gasoline Be Mixed with 92 Octane Gasoline?

[DeHaley]

92 octane gasoline and 95 octane gasoline cannot be mixed because they have different iso-octane contents. 92 octane gasoline is suitable for engines with low compression ratios, while 95 octane gasoline is suitable for engines with high compression ratios. If 92 octane gasoline is added to a car that should use 95 octane gasoline, abnormal combustion may occur, leading to engine knocking. Knocking not only damages the combustion chamber but also directly affects the normal operation of the engine, and in severe cases, may cause engine damage. If 95 octane gasoline is added to a car that should use 92 octane gasoline, although it will not damage the engine, 95 octane gasoline is more expensive than 92 octane gasoline, resulting in unnecessary costs. Differences between 92, 95, and 98 octane gasoline: Standard gasoline is composed of iso-octane and n-heptane. Iso-octane has good anti-knock properties, and its octane rating is set at 100. N-heptane has poor anti-knock properties and is prone to knocking in gasoline engines, so its octane rating is set at 0. If the gasoline is labeled as 92 octane, it means that the gasoline has the same anti-knock properties as standard gasoline containing 92% iso-octane and 8% n-heptane. The same principle applies to 95 and 98 octane gasoline. What to do if the wrong gasoline is added: If gasoline with a higher octane rating than the car's requirement is added (e.g., 95 octane instead of 92 octane), simply switch back to 92 octane gasoline after the current fuel is consumed. If gasoline with a lower octane rating than the car's requirement is added (e.g., 92 octane instead of 95 octane), you can add a high anti-knock fuel additive. Alternatively, you can drain the fuel tank and refill it with 95 octane gasoline. To find out which gasoline your car requires, refer to the car's user manual or check the fuel grade marked on the fuel filler cap.