a measure of the quality of a petrol expressed as the percentage of isooctane in a mixture of isooctane and n-heptane that gives a fuel with the same antiknock qualities as the given petrol
octane number in American English
octane rating
US
a number representing the antiknock properties of a gasoline, fuel mixture, etc., determined by the percentage of isooctane that must be mixed with normal heptane to produce the knocking quality of the fuel being tested: the higher the number, the greater the antiknock properties
octane number in Automotive Engineering
(ɒkteɪn nʌmbər)
noun
(Automotive engineering: Fuels, oils, emissions, and other fluids)
The octane number of a fuel, especially gasoline, is a measure of its anti-knock properties.
Gasoline characteristics that have an important effect on engines and emissions includeits octane number and chemical composition.
Gasoline is classified by its research octane number (RON). In Britain standard unleaded gasoline is 95RON.
The octane number represents a fuel's ability to resist engine knocking.
MeasurementsOther measurements used in the automotive industry include:BHPcetane numberhorsepowerspring rate