Is it okay to use 92-octane gasoline for the Jetta VS5?

[MacValeria]

Jetta VS5 can use 92-octane gasoline. This octane rating is recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline octane rating in the user manual, the Jetta VS5 also indicates it on the fuel tank cap. You can usually determine the suitable gasoline grade based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should use 92-octane gasoline, those between 10.0-11.5 should use 95-octane, and higher compression ratios may require 98-octane. However, with the application of new technologies, the compression ratio alone cannot determine the required gasoline grade, as high-compression engines can also be tuned to use lower-octane fuel. Other factors, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, the higher the gasoline octane rating, 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 you occasionally use the wrong gasoline octane rating in the Jetta VS5, simply switch back to the correct one after the current tank is used up. However, prolonged use of the wrong octane rating can have the following effects: For vehicles designed for lower-octane fuel, using higher-octane gasoline will not cause damage, but the increased octane number may 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 designed for higher-octane fuel, using lower-octane gasoline can cause engine knocking. The significantly lower octane number reduces the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance is generated during the upward stroke. This resistance makes the engine run very unstably. Mild knocking may only increase noise without obvious engine damage, but severe knocking indicates serious engine conditions, affecting not only driving stability but also causing abnormal wear to pistons and cylinders, and even cylinder scoring in extreme cases.