This standard establishes a research method for determining the octane number as a characteristic of the knock resistance of motor gasolines and their components intended for use in spark-ignition engines on a standardized single-cylinder, four-stroke carburetor engine with a variable compression ratio using a conventional octane number scale. As a standardized single-cylinder engine, installations of various types are currently used depending on the determination range, operating range and precision indicators, which make it possible to determine the octane number of motor fuels under standard operating conditions for the research method. This method can be used to determine octane numbers ranging from 0 to 120 units for Type I units, from 0 to 110 units for Types II, IV units, and from 0 to 100 units for Type III units. The operating range for type I installations is in the range from 40 to 120 units, for types II and IV installations – in the range from 40 to 110 units, for type III installations – in the range from 40 to 100 units. Typical commercial fuels for spark-ignition internal combustion engines have research octane numbers ranging from 80 to 101. When producing mixtures of gasoline or components, it may be necessary to estimate octane numbers using the research method outside the specified range. This standard can also be used to determine the octane numbers of fuels and their components containing oxygenates up to 4% by weight. by oxygen. The use of primary standard mixtures of isooctane with toluene or tetraethyl lead makes it possible to determine octane numbers above 100 units
GOST 8226-2022 history
2023GOST 8226-2022 Fuel for engines. Research method for determination of octane number
2015GOST 8226-2015 Fuel for engines. Research method for determination of octane number
1982GOST 8226-1982 Fuel for engines. Research method for determination of octane number