Should the 7th Generation Teana Naturally Aspirated Use 92 or 95 Octane Gasoline?

[McJace]

According to the official vehicle manual recommendation, the 7th Generation Teana Naturally Aspirated should use 92 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual for the 7th Generation Teana Naturally Aspirated, you can also find it on the fuel tank cap, which will also be marked. Generally, the fuel grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should choose 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should opt for 95 octane gasoline. However, with the use of some new technologies nowadays, the fuel grade cannot be solely determined by the compression ratio. A high compression ratio can also be tuned to use lower octane gasoline because, apart from the compression ratio, other factors come into play, such as ignition timing, turbocharging technology, and Atkinson cycle technology. Generally speaking, 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 7th Generation Teana Naturally Aspirated 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 lower octane gasoline, using higher octane gasoline by mistake will not cause damage, but the increase in octane number will alter the fuel's ignition point, leading to delayed combustion in the engine. This means the engine's power output and thermal efficiency will decrease, with the actual feedback being poorer performance. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. Because the octane number is much lower, 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's just mild knocking, the noise will increase, with no significant damage to the engine. However, if there is noticeable knocking, it indicates that the engine's condition is already very severe. The vibration not only affects driving stability but can also cause abnormal wear on the pistons and cylinders, and in severe cases, even cylinder scoring.