Can I Add 95 Octane Gasoline Before the 92 Octane is Completely Burned?
2 Answers
You should not add 95 octane gasoline before the 92 octane is completely burned. Here are the hazards of mixing different grades of gasoline: Abnormal exhaust pipe smoke: This may manifest as black smoke or blue smoke. After mixing, the gasoline may become thinner, making it easier to ignite in the cylinder, causing the engine to emit blue smoke. Mixing may also lead to poor cylinder sealing, resulting in black smoke from the engine. Accelerated sludge formation: Some sludge exists in the form of solid particles, which may accelerate engine wear or clog the oil filter and oil passages. This can lead to poor oil circulation and cause serious consequences. Discoloration of pistons: Mixed gasoline may alter its sealing properties, causing discoloration or damage to the piston rods or piston rings. Long-term use may severely wear the piston rods or piston rings, affecting the engine's lifespan.
I've driven quite a few cars and encountered this situation myself. It happened during a long-distance trip when I had about a quarter tank of 92-octane fuel left and directly topped up with 95-octane. After starting the engine, I felt it ran slightly smoother, but there wasn't any significant difference. Based on my experience, mixing fuels generally isn't problematic - the higher anti-knock properties of 95-octane can compensate for 92's limitations. However, if the vehicle manufacturer recommends 92-octane, long-term mixed usage might be wasteful since 95 is considerably more expensive. It's better to switch to a single fuel type during your next full refill to avoid occasional abnormal vibrations in the fuel system. Remember, always consult your vehicle's manual rather than believing online rumors. If you're truly concerned, have your fuel pump checked at an authorized service center.
