You are here: U.S.: overview of gasoline policy, market and qualityMarketSupply and demandPer octane grade
Per octane grade
There are three primary grades of on-road gasoline in the U.S.. Octane is not regulated federally, but most states regulate it, either explicitly or with reference to the National Science and Technology Institute Handbook’s 130 standards. The three grades are classified by anti-knock index (AKI), defined as the simple average of the octane ratings obtained via the RON and MON methods for the gasoline in question.
    •Regular grade generally meets a minimum limit of 87 AKI (i.e. (RON+MON)/2), although in some high-altitude regions that limit may drop to as low as 85 AKI (e.g. in parts of Utah and Nevada)
    •Midgrade, a blend of regular and premium grades, generally conforms to a minimum AKI of 89
    •Premium grade octane values generally range between 91 and 93 AKI, although a few sta
Contact us for full access
Per octane grade