nounMeasurementsOther measurements used in the automotive industry include:BHPcetane numberhorsepowerspring rate (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 include its 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.
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