What are the consequences of mixing CNPC and Sinopec gasoline?
2 Answers
Gasoline from different gas stations or brands can be mixed as long as they have the same octane rating. If the octane ratings are different, even if the gasoline is from the same brand, they should not be mixed. Mixing different octane ratings can lead to abnormal combustion, causing engine knocking. Knocking not only damages the combustion chamber but also directly affects the normal operation of the engine, and in severe cases, may lead to engine damage. To determine the appropriate octane rating for your vehicle, you can refer to the car's user manual or check the fuel rating marked on the fuel tank cap. How to handle adding the wrong gasoline: If you add gasoline with a higher octane rating than required by your car (e.g., adding 95 octane when 92 octane is specified), you can simply consume it normally and then refill with 92 octane gasoline. If you add gasoline with a lower octane rating than required (e.g., adding 92 octane when 95 octane is specified), you can add a high anti-knock fuel additive. Alternatively, you can drain the fuel and refill with the correct 95 octane gasoline.
I've been driving a taxi for over 20 years, and mixing PetroChina and Sinopec fuels is a common practice. To be honest, there are no serious consequences. Both gasolines meet national standards, and their additive compositions are largely similar. Occasionally mixing a tank won't affect engine startup or fuel consumption. I remember once during a long highway trip with few gas stations, I randomly refueled and used mixed fuels for several months without any issues. If there were major impacts, it would have made headlines. However, there are slight differences in additives—Sinopec has stronger cleaning properties while PetroChina offers better fuel economy. Mixing might slightly reduce cleaning effectiveness, but it doesn't hinder daily driving. For newer cars or high-precision engines, sticking to one brand is preferable to avoid unnecessary worries. In short, don't overthink it—cars aren't that delicate. Mixing is just for convenience; no need to deliberately avoid it.
