Oktaniarvon

Oktaniarvon is the Finnish term for octane value, a measure of a fuel's resistance to premature ignition in spark-ignition engines. In Finnish automotive and energy literature, it denotes the octane rating of gasoline and other fuels, informing performance expectations and engine compatibility.

Octane value is determined through standardized tests that yield numbers such as the Research Octane Number (RON) and the Motor Octane Number (MON). The commonly cited consumer figure is the RON, while in some North American contexts the AKI (anti-knock index) equals the average of RON and MON. In general discussion, oktaniarvon can refer to either metric, but practical labeling often emphasizes RON.

Higher oktaniarvon values indicate greater resistance to knocking, enabling higher compression ratios and potentially better efficiency and power in engines designed for higher-octane fuels. Fuel formulations, additives, and ethanol blends can influence the octane value.

In Europe, octane ratings are harmonized under standards such as EN 228, which defines performance requirements for petrol and methods for determining octane values. In Finland, oktaniarvon is used in regulatory and technical documents to specify fuel quality alongside the corresponding octane specification.

Related topics include octane rating, Research Octane Number, Motor Octane Number, AKI, and EN 228.