What are the consequences of using 92-octane gasoline in a Golf?

[SanJustin]

According to the official vehicle manual recommendation, the Golf should use 95-octane gasoline. Occasionally using 92-octane gasoline is acceptable as long as you switch back to the correct octane rating afterward. However, prolonged use of the wrong gasoline octane can have the following effects: For vehicles recommended to use lower octane gasoline, accidentally using higher octane gasoline will not cause damage. However, the increased octane rating alters the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power output and thermal efficiency, with the practical experience being noticeably poorer performance. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. Since the octane rating is significantly lower, the reduced ignition point causes premature combustion during the compression stroke. If the fuel ignites before the spark plug fires during the compression stroke, resistance occurs in the upward stroke. This resistance makes the engine run very unevenly. If the knocking is imperceptible, it only increases noise without obvious engine damage. However, noticeable knocking indicates severe engine operating conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, with severe cases potentially leading to cylinder scoring. In addition to checking the appropriate gasoline octane in the vehicle manual, Golf owners can also find this information on the fuel filler cap, which is usually labeled. Typically, the gasoline octane can also be determined based on the engine's compression ratio. Vehicles with a compression ratio between 8.6-9.9 should use 92-octane gasoline, while those with a compression ratio between 10.0-11.5 should use 95-octane gasoline. However, with the application of new technologies, the compression ratio alone cannot determine the required gasoline octane. High compression ratio engines can be tuned to use lower octane gasoline because, besides the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline octane, the higher the octane rating and the better the anti-knock performance. 92-octane gasoline contains 92% isooctane and 8% n-heptane, while 95-octane gasoline contains 95% isooctane and 5% n-heptane.