Should the GSX250 use 92 or 95 octane fuel?
1 Answers
According to the official vehicle manual recommendation, the GSX250 should use 92 octane gasoline. In addition to checking the appropriate fuel grade in the vehicle manual, you can also find it on the fuel tank cap, which will also be indicated. Generally, the fuel 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. However, with the application of some new technologies, the fuel grade cannot be solely determined by the compression ratio. A high compression ratio can also be tuned to use lower octane fuel. This is 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 fuel 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 GSX250 occasionally uses the wrong fuel grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong fuel grade can have the following effects: For vehicles recommended to use lower octane fuel, using higher octane fuel will not cause damage, but the increase in octane number will alter 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 practice. For vehicles recommended to use higher octane fuel, using lower octane fuel can cause engine knocking. Because the octane number is too low, the fuel's ignition point decreases, causing premature ignition during the compression stroke. If the fuel ignites before the spark plug fires during the compression stroke, resistance will occur during the upward stroke. This resistance makes the engine run very unstably. If the knocking is imperceptible, it only increases noise without significant damage to the engine. However, noticeable knocking indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.