What grade of gasoline should the Bora use?

[VanElena]

The Bora 1.5L should use 92-octane gasoline, while the 1.2L and 1.4L models should use 95-octane gasoline. These gasoline grades are recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, you can also find it on the fuel tank cap, which will also indicate the recommended grade. Typically, the 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. If the compression ratio is higher, 98-octane gasoline is recommended. However, with the use of new technologies, the compression ratio alone cannot determine the gasoline grade, as high-compression engines can also be tuned to use lower-octane gasoline. 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 rating 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 refueling. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles designed for lower-octane gasoline, using higher-octane gasoline will not cause damage, but the increased octane rating 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 lower-octane gasoline can cause engine knocking. The significantly lower octane rating lowers the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug ignites, resistance is created during the upward stroke. This resistance makes the engine run very unevenly. Mild knocking may only increase noise without significant engine damage, but noticeable knocking indicates severe engine conditions. The vibrations not only affect driving stability but also cause abnormal wear on the pistons and cylinders, potentially leading to cylinder scoring in severe cases.