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 engine octane number (MOZ) is a measure of the knock resistance of gasoline for automobile engines under difficult operating conditions. With regard to aviation fuels for aircraft piston engines, the engine octane number provides a measure of knock resistance by using an equation to correlate it with the octane number for flight operations ("aviation method") or with the performance number for flight operations (lean mixture testing of aviation fuel; "lean mixture aviation rating") is produced. This International Standard is applicable to the entire scale range from 0 MOZ to 120 MOZ, but the working range is between 40 MOZ and 120 MOZ. The typical test range for gasoline is 80 MOZ to 90 MOZ. The typical testing range for aviation fuels is 98 MOZ to 102 MOZ. This International Standard is applicable to fuels containing oxygenated compounds with an oxygen content of up to 4% (m/m) and to gasoline fuels with an ethanol content of 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 feasibility of applying the method to petrol with an ethanol content of up to 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. ANNOTATION
EN ISO 5163:2014 Referenced Document
ASTM D2699-13 Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel*， 2024-04-20 Update
ASTM D2700-12 Standard Test Method for Motor Octane Number of Spark-Ignition Engine Fuel*， 2024-04-20 Update
ISO 3171:1988 Petroleum liquids; automatic pipeline sampling
ISO 3696:1987 Water for analytical laboratory use; Specification and test methods
ISO 4787:2010 Laboratory glassware - Volumetric instruments - Methods for testing of capacity and for use
EN ISO 5163:2014 history
2014EN ISO 5163:2014 Petroleum products - Determination of knock characteristics of motor and aviation fuels - Motor method (ISO 5163:2014)
2005EN ISO 5163:2005 Petroleum products - Determination of knock characteristics of motor and aviation fuels - Motor method [Superseded: CEN EN 25163] [Use: IP 236/2005]