Definition of octane number in English:

octane number

Syllabification: oc·tane num·ber
(also octane rating)


  • A figure indicating the antiknock properties of a fuel, based on a comparison with a mixture of isooctane and heptane.
    More example sentences
    • In particular, the formation of branched alkanes increases the octane number and combustibility of the resulting hydrocarbon.
    • Using a fuel of a higher octane rating than that recommended for your car doesn't improve its performance.
    • The higher the octane number you see on a gas pump, the more the fuel can be compressed before it explodes.

More definitions of octane number

Definition of octane number in:

Get more from Oxford Dictionaries

Subscribe to remove ads and access premium resources

Word of the day coloratura
Pronunciation: ˌkələrəˈto͝orə
elaborate ornamentation of a vocal melody