What Octane Gasoline Should the Volkswagen Talagon Use?

[RebeccaMarie]

The Volkswagen Talagon with a 2.0T four-cylinder engine requires 98 octane gasoline, while the six-cylinder version can use 95 octane gasoline. These octane ratings are recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline octane in the user manual, you can also find it indicated on the fuel tank cap. Typically, the required octane 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, those between 10.0-11.5 should use 95 octane, and higher compression ratios require 98 octane. However, with the use of new technologies, the compression ratio alone may not determine the required octane, as high compression ratios can sometimes be tuned to use lower octane gasoline. Other factors, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, higher octane gasoline has a higher octane rating and better anti-knock properties. For example, 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Talagon occasionally uses the wrong octane gasoline, simply switching back to the correct octane after use is sufficient. However, prolonged use of the wrong octane can have the following effects: Using higher octane gasoline in a vehicle designed for lower octane will not cause damage, but the increased octane can alter the fuel's ignition point, leading to delayed combustion. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. Using lower octane gasoline in a vehicle designed for higher octane can cause engine knocking. The lower octane reduces the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance builds up during the upward stroke. This resistance makes the engine run very unevenly. Mild knocking may only increase noise without significant engine damage, but severe knocking indicates serious engine issues, affecting driving stability and causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring.