What octane gasoline should a Bora use?
1 Answers
The Bora 1.5L should use 92 octane gasoline, while the 1.2L and 1.4L models should use 95 octane gasoline, as recommended in the vehicle's official owner's manual. In addition to checking the owner's manual for the appropriate gasoline grade, you can also find this information 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 a compression ratio between 8.6-9.9 should use 92 octane gasoline, those with a compression ratio between 10.0-11.5 should use 95 octane gasoline, and if the compression ratio is higher, 98 octane gasoline is recommended. However, with the application of new technologies nowadays, 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, 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 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 the Bora occasionally uses the wrong gasoline grade, simply switch back to the correct grade after the current tank is used up. However, prolonged 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 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 designed for higher octane gasoline, using a lower octane grade can cause engine knocking. Because the octane value is significantly lower, the reduced ignition point may cause the gasoline to ignite prematurely during the compression stroke. If combustion occurs before the spark plug fires, resistance will develop during the upward stroke. This resistance makes the engine run very unevenly. If the knocking is mild, 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 the pistons and cylinders, and in severe cases, cylinder scoring.
