Does 95 Octane Gasoline Provide More Power?

[DeCarlos]

Not exactly. The octane rating of gasoline only indicates its anti-knock performance and is not directly related to power output. Therefore, it's essential to follow the vehicle manufacturer's recommendations in the owner's manual when selecting the appropriate gasoline grade. In addition to checking the owner's manual for the recommended gasoline grade, you can also find this information on the fuel filler cap. Generally, the gasoline grade 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. However, with the application of new technologies, the compression ratio alone cannot determine the appropriate gasoline grade. High compression ratio engines can be tuned to use lower octane gasoline because other factors, such as 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. Occasionally using the wrong gasoline grade is not a problem as long as you switch back to the correct grade after consumption. However, prolonged use of the wrong gasoline grade can have the following effects: For vehicles designed for lower octane gasoline, using higher octane gasoline will not cause damage, but the increased octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power and thermal efficiency, which translates to poorer performance. For vehicles designed for higher octane gasoline, using lower octane gasoline can cause engine knocking. Since the octane number is significantly 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, resistance occurs during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, it may only increase noise without significant damage to the engine. 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.