Chemistry

  1. Home
  2. Education
  3. Chemistry

Octane Number Definition

Chemistry Glossary Definition of Octane Number

By Anne Marie Helmenstine, Ph.D., About.com

Return to the Chemistry Glossary Index

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Definition: 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.

Explore Chemistry

About.com Special Features

How to Ace the GRE

Being well prepared is the first step; here are more essential suggestions. More >

The Business School Lowdown

Everything from choosing a school and applying, to employment after graduation. More >

Chemistry

  1. Home
  2. Education
  3. Chemistry
  4. Facts & Pictures
  5. Dictionaries & Glossaries
  6. Chemistry Glossary
  7. Octane Number Definition - Chemistry Glossary Definition of Octane Number

©2009 About.com, a part of The New York Times Company.

All rights reserved.