What Octane Gasoline Should Nissan Sylphy Use?

[LeVanessa]

Nissan Sylphy should use 92 octane gasoline. This octane rating is recommended in the vehicle's official owner's manual. In addition to checking the owner's manual for the appropriate gasoline octane, Nissan Sylphy owners can also find this information on the fuel tank cap, which will be clearly marked. Generally, the octane rating can also be determined based on the engine's compression ratio. Vehicles with a 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 even higher, 98 octane gasoline is recommended. However, with the use of new technologies, the octane rating cannot be solely determined by the compression ratio. Engines with high compression ratios can also be tuned to use lower octane gasoline, as factors like ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the octane rating, 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 Nissan Sylphy occasionally uses the wrong octane gasoline, simply switching back to the correct octane after the tank is empty is sufficient. However, long-term use of the wrong octane gasoline can have the following effects: For vehicles recommended to use lower octane gasoline, using higher octane gasoline will not cause damage, but the increased octane number may alter the fuel's ignition point, leading to delayed combustion in the engine. This can reduce the engine's power output and thermal efficiency, resulting in poorer performance. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. Due to the significantly lower octane number, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance will occur during the upward stroke. This resistance makes the engine run very unstably. Mild knocking may only increase noise without noticeable engine damage, but severe knocking indicates serious engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.