Is it necessary to use 95 octane gasoline for the 2021 CR-V?

[VanFelicity]

According to the official vehicle manual recommendation, the 2021 CR-V should use 92 octane gasoline, so there is no need to use 95 octane gasoline. For the 2021 CR-V, in addition to checking the suitable gasoline grade in the vehicle manual, you can also check the fuel tank cap, which will also indicate the recommended gasoline grade. 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. However, with the use of some new technologies nowadays, the gasoline grade cannot be solely determined by the compression ratio. A high compression ratio can also be adjusted to use lower octane gasoline. This is because, apart from 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 2021 CR-V 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 higher octane gasoline will not cause damage, but the increase in octane value will change the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. This is because the significantly lower octane value reduces the gasoline's ignition point, causing it to ignite prematurely during the compression stroke. If the fuel ignites before the spark plug fires, resistance will occur during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, it may only increase noise without obvious damage to the engine. However, if the knocking is severe, it indicates serious engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.