What Grade of Gasoline is Suitable for the Sagitar?

[Susan]

The Sagitar should use 95-octane gasoline. This gasoline grade is recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, you can also find it marked on the fuel tank cap. Typically, the gasoline grade 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. If the compression ratio is even higher, 98-octane gasoline is recommended. However, with the application of new technologies, the compression ratio alone cannot determine the appropriate gasoline grade, as high-compression engines can also be tuned to use lower-octane gasoline. This is because 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 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. If the Sagitar occasionally uses the wrong gasoline grade, simply switch back to the correct grade after the tank is empty. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-octane gasoline, accidentally using higher-octane gasoline will not cause damage, but the increased octane rating can 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. For vehicles recommended to use higher-octane gasoline, using lower-octane gasoline can cause engine knocking. Due to the significantly lower octane rating, the fuel ignites prematurely during the compression stroke, creating resistance before the spark plug fires. This resistance makes the engine run very unevenly. If the knocking is mild, it may only increase noise without obvious engine damage. However, severe knocking indicates serious engine issues, affecting not only driving stability but also causing abnormal wear to the pistons and cylinders, potentially leading to cylinder scoring.