Should the Mercedes-Benz C260L use 92 or 95 octane gasoline?
1 Answers
According to the official vehicle user manual recommendation, the Mercedes-Benz C260L should use 95 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle user manual, the Mercedes-Benz C260L can also refer to the fuel filler cap, which will indicate the recommended grade. Typically, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine 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. If the compression ratio is higher, 98 octane gasoline is recommended. However, with the application of new technologies, the gasoline grade cannot be solely determined by the compression ratio. Engines with high compression ratios can also be tuned to use lower-octane gasoline because, apart from the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, 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 Mercedes-Benz C260L occasionally uses the wrong gasoline grade, simply switch back to the correct grade after the current tank is used up. However, prolonged use of the wrong gasoline grade can have the following effects: For vehicles designed for lower-octane gasoline, using a higher-octane grade will not cause damage, but the increased octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power and thermal efficiency, with the practical effect being poorer performance. For vehicles designed for higher-octane gasoline, using a lower-octane grade can cause engine knocking. Because the octane number is significantly lower, the reduced ignition point may cause the gasoline to ignite prematurely during the compression stroke. If the fuel ignites before the spark plug fires, resistance will occur during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, it may only increase noise without obvious damage to the engine. However, if the knocking is severe, it indicates serious engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.
