What Octane Gasoline Should a Sagitar Use?

[Hailey]

Volkswagen Sagitar should use 95 octane gasoline, as this fuel 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 on the fuel tank cap, which will be clearly marked. Generally, 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 compression ratio alone cannot determine the gasoline grade, as high compression ratios can also be tuned to use lower octane gasoline. Other factors, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, the higher the gasoline octane number, the higher the octane value 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 you occasionally use the wrong gasoline grade in a Volkswagen Sagitar, simply switch back to the correct grade after the current tank is used up. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower octane gasoline, using a higher octane grade will not cause damage, but the increased octane value 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 a lower octane grade can cause engine knocking. Due to the significantly lower octane value, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If the fuel ignites before the spark plug fires, resistance occurs during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, it may only increase noise without significant engine damage. However, noticeable knocking indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring in severe cases.