Should the Lingpai use 92 or 95 octane gasoline?

[McAlessandra]

According to the official car manual recommendation, the Lingpai should use 92 octane gasoline. In addition to checking the suitable gasoline grade in the car manual, you can also find it on the fuel tank cap, which will also be marked. Usually, the gasoline grade can also be determined based on the engine's compression ratio. Cars with an engine compression ratio between 8.6-9.9 should choose 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should choose 95 octane gasoline. If the compression ratio is higher, 98 octane gasoline should be selected. However, with the use of some new technologies nowadays, the gasoline grade cannot be determined solely based on the compression ratio. A high compression ratio can also be adjusted to use lower-grade gasoline. This is because, besides the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally speaking, the higher the gasoline grade, the higher the octane number 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. If the Lingpai occasionally uses the wrong gasoline grade, simply switch back to the correct grade after use. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-grade gasoline, using higher-grade gasoline will not cause damage, but the increase in octane number will change the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance in actual driving experience. For vehicles recommended to use higher-grade gasoline, using lower-grade gasoline can cause engine knocking. Because the octane number is too low, the gasoline's ignition point decreases and may ignite prematurely during the compression stroke. If detonation occurs before the spark plug ignites during the compression stroke, resistance will appear in the upward stroke. This resistance will make the engine run very unstably. If it's just mild knocking with increased noise, the damage to the engine is not significant. However, if there is obvious knocking, it indicates that the engine's condition is already very severe. The vibration not only affects driving stability but can also cause abnormal wear on the piston and cylinder, and in severe cases, even cylinder scoring.