This International Standard specifies the evaluation of liquid fuels for gasoline engines, specified according to an arbitrarily selected scale of octane numbers, using a standardized CFR (single cylinder, four-stroke, variable compression ratio, carbureted) engine operating at constant speed. The research octane number (RON) is a measure of the knock resistance of gasoline for automobile engines under light operating conditions. This International Standard is applicable to the entire scale range from 0 RON to 120 RON, but the working range is between 40 RON and 120 RON. The typical test range for gasoline is 88 RON to 101 RON. This International Standard is applicable to fuels containing oxygenated compounds with an oxygen content of up to 4.0% (m/m) to petrol fuels with a content of up to 25% (v/v). NOTE 1 Although an ethanol content of 25% (v/v) corresponds approximately to an oxygen content of 9% (m/m), the full applicability of this test method for this oxygen range has only been tested for gasoline fuels. NOTE 2 Reviews of the possibility of applying the method to petrol containing ethanol up to and including 85% (v/v) are currently underway. NOTE 3 This International Standard specifies operating conditions in SI units, but the dimensions of the engine may be in inch-pound units since these were the manufacturing dimensions for the equipment; therefore, some references in this International Standard include these units in parentheses. NOTE 4 For the purposes of this standard, the expressions "% (m/m)" and "% (V/V)" are used to indicate % by mass (µ) and % by volume (), respectively.
EN ISO 5164:2014 Referenced Document
ASTM D2699-12 Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel*， 2024-04-20 Update
ASTM D2699-13 Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel*， 2024-04-20 Update