Can 98 Octane and 95 Octane Gasoline Be Mixed?
2 Answers
98 octane and 95 octane gasoline cannot be mixed for use. The hazards of mixing include: affecting the normal operation of the engine, leading to increased car noise, reduced driving power, and potential engine damage. Gasoline is a volatile, flammable liquid hydrocarbon mixture obtained from the distillation, cracking, or pyrolysis of petroleum, used as fuel. Gasoline is classified into different grades based on octane ratings, such as 89, 90, 92, 93, 95, 97, and 98. Characteristics of gasoline: 1. Volatility: In the engine cylinder, it quickly vaporizes and forms a uniform combustible mixture with air. 2. Stability: The ability to resist oxidation under normal temperature and liquid phase conditions is called stability. 3. Anti-knock property: Refers to the gasoline's ability to resist detonation combustion under various usage conditions. 4. Corrosiveness: Sulfur compounds in gasoline can cause corrosion to materials.
Over the past decade of driving, I've experienced several instances of mixing 98 and 95 octane gasoline. When the gas station ran out of 98 octane, I had to fill my high-compression ratio engine car with 95 octane. After starting the engine, the noise increased noticeably, accompanied by slight vibrations, which felt abnormal. Consulting a car-savvy friend, he explained that the octane rating determines anti-knock capability—98 octane is higher than 95, and mixing them reduces the average anti-knock performance, leading to engine knocking. Prolonged use could damage engine components. Mixed fuel may also increase fuel consumption, wasting money instead. In emergencies, mixing a small amount is acceptable due to residual fuel in the lines, but habitual mixing is strongly discouraged. The manufacturer's specified fuel grade is optimized for engine design, ensuring smooth power delivery and safe driving. Following the manual is key to maintaining vehicle health.
