An Octane Number or Octane Rating is a standard measure of a fuel's ability to resist knock that denotes the percentage (by volume) of iso-octane (a type of octane) in a combustible mixture (from iso-octane (100) and heptane (0)). The Octane requirement of an engine varies with compression ratio, geometrical and mechanical considerations, and operating conditions. The higher the octane number the greater the fuel’s resistance to knocking or pinging during combustion.
Related Definitions in the Project: The Property and Unit
