Can 92 and 95 gasoline be mixed for use?
2 Answers
95 and 92 gasoline cannot be mixed. 95-octane gasoline is suitable for engines with high compression ratios. If 92-octane gasoline is used in a high-compression engine, it may cause abnormal combustion, knocking, and even engine seizure. Additionally, carbon deposits will accumulate faster than usual, leading to insufficient power, engine wear, or even complete failure. Since gasoline is a mixture and the chemical compositions of both types are relatively similar, it is recommended to use them separately to ensure vehicle safety. The difference between 92 and 95 gasoline lies in their octane ratings and quality levels. The details are as follows: Difference in octane rating: 92-octane gasoline contains 92% isooctane and 8% n-heptane. 95-octane gasoline contains 95% isooctane and 3% n-heptane. Difference in gasoline quality: The octane number of gasoline represents its octane rating. A higher octane number indicates a higher octane rating, which means better anti-knock performance. This allows the engine to run more smoothly, reduces wear and tear, and provides better protection for the engine. It is recommended that vehicles requiring lower-octane gasoline will not be damaged if higher-octane gasoline is accidentally used. However, the increase in octane rating may alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. Using lower-octane gasoline in vehicles designed for higher-octane fuel may cause engine knocking. Because the octane rating is too low, the lowered ignition point may cause premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance will arise during the upward stroke, making the engine run very unstably. Mild knocking may only increase noise without obvious engine damage, but severe knocking indicates serious engine issues, affecting driving stability and causing abnormal wear on pistons and cylinders, or even cylinder scoring in severe cases. If you accidentally mix fuels or use the wrong octane gasoline, simply refill with the correct octane gasoline next time to restore normal operation. Some drivers believe that using higher-octane gasoline can improve performance, but this is unnecessary because if the engine's compression ratio does not meet the standard, even premium fuel will not make a difference. At best, it may slightly reduce carbon emissions and keep the engine cleaner.
I've been driving for many years, and the manufacturer recommends 95-octane fuel, but in small towns, sometimes only 92-octane is available. I've mixed them a few times. It doesn't seem to be a big issue—the engine sounds normal, and the acceleration is smooth. I checked the information: 92 and 95 have different octane ratings, and mixing them results in around 93. The car's computer automatically adjusts the ignition timing to prevent knocking, so it can handle it for a while. However, doing this long-term isn't recommended, as it can increase carbon buildup and slightly raise fuel consumption, costing more in the long run. For the car's longevity, it's better to stick to the manual and not cut corners. Last time during maintenance, the mechanic said mixing occasionally by mistake is fine, but don't make it a habit—saving a few bucks on fuel isn't worth it.
