Does adding 95 octane gasoline to half a tank of 92 octane have any impact?
2 Answers
There is a certain impact when adding 95 octane gasoline to a half tank of 92 octane gasoline. Occasionally adding the wrong gasoline grade only requires switching back to the correct grade after use, but long-term use of the wrong gasoline grade should be avoided. Long-term use of the wrong gasoline grade can have the following effects: For vehicles designed for lower octane gasoline, using higher octane gasoline will not cause damage, but the increase in octane rating can alter the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in a noticeable drop in performance. For vehicles designed for higher octane gasoline, using lower octane gasoline can cause engine knocking. Because the octane rating is too low, the gasoline's ignition point decreases, causing it to ignite prematurely during the compression stroke. If the fuel ignites before the spark plug fires, resistance will occur during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, it may only increase noise without significant damage to the engine. However, if severe knocking occurs, it indicates serious engine issues, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring. Hazards of using the wrong fuel: Using higher octane fuel in a vehicle designed for lower octane fuel: The car may experience reduced power and higher fuel consumption, but as long as it is not used long-term, it will not cause significant damage. Conversely, using lower octane fuel in a vehicle designed for higher octane fuel generally has no impact. Adding gasoline to a diesel vehicle: The car may start, but due to incomplete combustion of gasoline, it will become increasingly sluggish while driving, leading to power loss, shaking, and white smoke. In such cases, the fuel system must be thoroughly cleaned. Adding diesel to a gasoline vehicle: The vehicle will fail to start. Diesel has a lower ignition point, and while gasoline requires spark ignition, diesel ignites under compression. The ignition system will directly ignite the diesel, causing knocking, engine damage, black smoke, vehicle shaking, and failure to start. In severe cases, the engine may be damaged. In such situations, contact a repair shop to clean the fuel system.
Oh, this question reminds me of my own driving experience. I drive an old family car, and the manual recommends using 92-octane gasoline. Once when the tank was only half full, I added some 95-octane to try it out. For those few days, I didn't notice any significant changes while driving—the engine sound was normal, and there was no delay in acceleration. However, later when I looked it up, I learned that mixing gasoline with different octane ratings might cause incomplete combustion in the engine, slightly increasing fuel consumption. If the car is more finely designed, like a turbocharged model, mixed fuel could lead to more carbon deposits, which might affect component lifespan over time. So now I've developed the habit of waiting until the tank is nearly empty before refueling, to avoid mixing fuels and stressing the car. It's safest to stick to the recommended octane rating when refueling—saving both money and hassle.
