Octane: Meaning (information, definition, explanation, facts)

Octane is an organic chemical, specifically an alkane, with formula C₈H₁₈. (8 carbon alkene).  Octane has many isomers.  One of those isomers, isooctane (2,2,4-trimetylpentane), is especially important, because its octane rating is by definition 100.  It is an important constituent of petrol (US:gasoline).

Octane ratings are ratings used to represent the anti-knock performance of petrol by giving the percentage of octane in an octane-heptane mixture that would have the same performance.

See also: cetane in diesel.