What grade of gasoline should a Polo use?
1 Answers
polo should use 92-octane gasoline, as this fuel grade is recommended in the vehicle's official owner's manual. In addition to checking the suitable gasoline grade in the owner's manual, Polo owners can also find this information on the fuel tank cap, which is typically labeled. Generally, the appropriate 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. For higher compression ratios, 98-octane gasoline is recommended. However, with the application of some new technologies, the compression ratio alone cannot determine the appropriate gasoline grade. Engines with high compression ratios can also be tuned to use lower-octane gasoline. This is because factors other than compression ratio, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, the higher the gasoline 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 a Polo is occasionally filled with the wrong gasoline grade, simply switching back to the correct grade after use is sufficient. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles designed for lower-octane gasoline, using a higher-octane grade will not cause damage, but the increase in octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power and thermal efficiency, with the practical effect being poorer performance. For vehicles designed for higher-octane gasoline, using a lower-octane grade can cause engine knocking. Because the octane number is significantly lower, the gasoline's ignition point decreases, causing it to ignite prematurely during the compression stroke. If combustion occurs before the spark plug fires during the compression stroke, resistance will develop during the upward stroke. This resistance makes the engine run very unevenly. If the knocking is imperceptible, it may only increase noise without obvious 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.
