Does mixing 92 and 95 gasoline once have any impact?
2 Answers
Mixing them once or twice has little effect. Below is an introduction about 92 and 95 gasoline: Difference: The octane number of the fuel is different, and different octane numbers correspond to different anti-knock indexes. That is to say, gasoline with a higher grade has better anti-knock performance. Impact: Long-term mixing of gasoline with different grades will affect the service life of the car's ignition system, fuel injector, and spark plug, advancing the vehicle's major repair time. Strictly speaking, 92 and 95 gasoline should not be mixed, but their chemical composition and other aspects are relatively similar, with strong anti-knock performance. Generally, mixing them will not cause any major problems. After short-term mixing of gasoline with different grades, special maintenance of the vehicle is usually not required. However, it is recommended that car owners strictly use the corresponding grade of gasoline as required by the vehicle itself when conditions permit. For example, adding 95 gasoline to a car that originally uses 92 gasoline generally will not cause problems, but the opposite may lead to vehicle damage. Using low-grade gasoline may cause vehicle vibration, and in severe cases, it may lead to problems such as valve bending and valve cover damage.
Having worked in automotive repair for many years, I've seen many friends or customers accidentally mix 92 and 95 octane gasoline. A one-time issue usually doesn't have much impact. The reason is that modern car ECUs (Engine Control Units) are quite intelligent and can automatically adjust ignition timing based on the gasoline's octane rating to prevent knocking. Knocking refers to abnormal engine noises and vibrations. When lower-octane fuel like 92 is mixed in, the octane rating is lower. If the car is designed for 95 octane, there's a theoretical risk of slightly increased knocking, but with just one mix-up, the computer adapts quickly without causing long-term damage. However, I recommend monitoring the engine's performance—check if acceleration is smooth and if there are any unusual noises. If not, there's no need to worry too much. Long-term mixing is more harmful, potentially leading to carbon buildup or affecting sensors, which impacts fuel efficiency and performance. Next time you refuel, it's best to stick with the manufacturer's recommended octane rating—for example, if your car's manual specifies 95 octane, always use 95 to ensure healthy engine operation. Occasional mistakes happen to everyone, so don't be too hard on yourself. Cleaning the fuel system might cost just a few dozen dollars, but in most cases, no special treatment is needed.
