What Octane Gasoline Should a Normal Car Use?

[Valarie]

The selection of gasoline octane rating should be determined by the compression ratio of the car's engine. The appropriate fuel octane rating for the vehicle is usually indicated on the inside of the fuel tank cap. If it specifies 92-octane fuel, then use 92-octane. If it specifies 95-octane fuel, then use 95-octane. Whether the gasoline is 92 or 95 octane, the number represents the fuel's anti-knock performance. A higher octane rating indicates better anti-knock performance, but it does not necessarily mean higher fuel quality, contrary to the common belief that higher octane fuel is always better. For naturally aspirated engines, 92-octane gasoline is generally recommended. Higher-octane fuel has better anti-knock performance but burns relatively slower, which can lead to higher compression ratios in the engine, resulting in reduced power and increased temperatures. For turbocharged engines, manufacturers typically recommend 92-octane or higher. Using 95-octane gasoline not only ensures higher torque at low speeds but also helps reduce engine vibration and noise.