Should the Volkswagen Bora use 92 or 95 gasoline?
1 Answers
According to the official car manual recommendation, the Volkswagen Bora should use 92 gasoline. In addition to checking the suitable gasoline grade in the car manual, you can also check the fuel tank cap, which will also indicate the recommended gasoline grade. Usually, the gasoline grade can also be determined based on the engine's compression ratio. Cars with an engine compression ratio between 8.6-9.9 should choose 92 gasoline, while those with a compression ratio between 10.0-11.5 should choose 95 gasoline. However, with the use of some new technologies, the gasoline grade cannot be determined solely by the compression ratio. A high compression ratio can also be adjusted to use low-grade gasoline because, besides the compression ratio, other 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 number and the better the anti-knock performance. 92 gasoline contains 92% isooctane and 8% n-heptane, while 95 gasoline contains 95% isooctane and 5% n-heptane. If the Volkswagen Bora occasionally uses the wrong gasoline grade, simply switch back to the correct grade after using it up. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use low-grade gasoline, using high-grade gasoline by mistake will not cause damage, but the increase in octane number will change the fuel's ignition point, leading to delayed combustion in the engine. This means the engine's power output and thermal efficiency will decrease, resulting in poorer performance. For vehicles recommended to use high-grade gasoline, using low-grade gasoline can cause engine knocking. Because the octane number is too low, the gasoline's ignition point decreases, causing it to ignite prematurely during the compression stroke. If the fuel ignites before the spark plug fires during the compression stroke, resistance will occur during the upward stroke. This resistance will make the engine run very unstably. If it is mild knocking, it will only increase noise and cause minimal damage to the engine. However, if there is noticeable knocking, it indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on the pistons and cylinders, and in severe cases, cylinder scoring.
