What do gasoline grades 95, 92, and 98 mean?

[BethanyDella]

Gasoline grades 92, 95, and 98 represent different levels of isooctane content in the fuel, while the fuel quality and the heat value per unit volume remain the same. Octane Rating: The numbers indicate the octane rating of the gasoline. The higher the number, the higher the octane rating, which means the gasoline has better anti-knock properties. For example, 92-grade gasoline contains 92% octane, 95-grade contains 95%, and 98-grade contains 98%. Anti-Knock Properties: When the air-fuel mixture is injected into the cylinder, the piston compresses the mixture, increasing pressure and temperature. If the gasoline's anti-knock properties are too low, the mixture may ignite before the spark plug fires, leading to uncontrolled combustion, commonly known as knocking. Higher octane ratings provide better anti-knock properties, reducing potential engine damage.