Can the Toyota Sienna use 92 octane gasoline?

[VonSimon]

According to the official vehicle manual recommendations, the Toyota Sienna should not use 92 octane gasoline; it requires 95 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual, you can also find this information on the fuel tank cap, where it is usually indicated. Typically, the suitable 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, those 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, the compression ratio alone cannot determine the required gasoline grade. High compression ratio engines can also be tuned to use lower octane gasoline, as 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 Toyota Sienna 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 recommended to use lower octane gasoline, using a higher octane grade will not cause damage, but the increase in octane value 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 practical effect being poorer performance. For vehicles recommended to use higher octane gasoline, using a lower octane grade can cause engine knocking. Due to the significantly lower octane value, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires during the compression stroke, resistance will develop in the upward stroke. This resistance makes the engine run very unstably. 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.