Should the Lincoln Nautilus use 95 or 92 octane gasoline?

[StHadley]

The Lincoln Nautilus can use 92 octane gasoline. This octane rating is recommended in the vehicle's official owner's manual. In addition to checking the appropriate gasoline octane in the owner's manual, the recommended octane rating is also indicated on the fuel tank cap. Generally, the required octane 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. If the compression ratio is even higher, 98 octane gasoline is recommended. However, with the use of new technologies, the compression ratio alone cannot determine the required octane rating. High compression ratio engines can still 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 octane, 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 Lincoln Nautilus occasionally uses the wrong octane gasoline, simply switch back to the correct octane after the current tank is used up. However, prolonged use of the wrong octane can have the following effects: For vehicles designed for lower octane, using higher octane gasoline will not cause damage, but the increased octane can alter the fuel's ignition point, leading to delayed combustion. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. For vehicles designed for higher octane, using lower octane gasoline can cause engine knocking. The significantly lower octane reduces the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance is created during the upward stroke. This resistance makes the engine run very unstably. Mild knocking may only increase noise without obvious engine damage, but severe knocking indicates serious engine issues, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, potentially leading to severe damage like cylinder scoring.