1. Education
Send to a Friend via Email

Discuss in my forum

Octane Number Definition

Chemistry Glossary Definition of Octane Number

By

Definition: Octane number is a value used to indicate the resistance of a motor fuel to knock. Octane numbers are based on a scale on which isooctane is 100 (minimal knock) and heptane is 0 (bad knock).

Also Known As: Octane Rating

Examples: A gasoline with an octane number of 92 has the same knock as a mixture of 92% isooctane and 8% heptane.

Return to the Chemistry Glossary Index

©2014 About.com. All rights reserved.