cetane number

noun

1. a measure of the ignition quality of a diesel engine fuel by comparison with various mixtures in which the alpha form of methylnaphthalene is given a standard value of 0 and cetane is given a standard value of 100.

noun

1. a measure of the quality of a diesel fuel expressed as the percentage of cetane in a mixture of cetane and 1-methylnapthalene of the same quality as the given fuelAlso called: cetane rating Compare octane number