What grade of gasoline should the new Highlander use?
1 Answers
The new Highlander should use 95-octane gasoline, as this is the recommended grade specified in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, you can also find it marked on the fuel tank cap of the new Highlander. Generally, 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 application of new technologies, the gasoline grade cannot be solely determined by the compression ratio. High compression ratio engines can also be tuned to use lower-octane gasoline due to other influencing factors such as ignition timing, turbocharging technology, and Atkinson cycle technology. 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 the new Highlander occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-octane gasoline, using a higher grade will not cause damage, but the increased 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 actual experience being poorer performance. For vehicles recommended to use higher-octane gasoline, using a lower grade can cause engine knocking. Because the octane number is too low, the reduced ignition point may cause premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance will be generated during the upward stroke. This resistance makes the engine run very unstable. If the knocking is mild, it may only increase noise without significant engine damage. 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.
