Can a Car Designed for 92 Octane Gasoline Use 95 Octane?
2 Answers
A car designed for 92 octane gasoline can occasionally use 95 octane, but long-term use may cause damage to the vehicle. Mixing lower octane gasoline with higher octane gasoline can lead to issues such as engine knocking, insufficient power, and may shorten the lifespan of spark plugs, as well as increase exhaust emissions. Gasoline is a mixture, and the difference between 92 and 95 octane gasoline lies in the ratio of n-heptane and isooctane: 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane.
Of course you can use 95 octane gasoline. My car's manual recommends 92 octane, but I often fill up with 95 for long trips—the engine runs quieter and the power delivery feels smoother. The gasoline grade simply indicates the octane rating; 95 has better anti-knock properties, meaning it burns more stably under high temperature and pressure without harming the engine. However, it’s noticeably more expensive—each refill costs an extra 20-30 RMB. I’ve calculated that fuel efficiency remains largely unchanged, so from a cost-saving perspective, it’s a bit wasteful. For regular city driving, sticking with 92 octane is perfectly fine—no need to upgrade. But if a gas station only has 95, filling up once won’t cause any issues. Even long-term mixed usage isn’t a big deal; the car’s electronic system will adjust automatically, which gives me peace of mind.