Question

What is octane number and how to find it❓

Answer 1

octane number, also called Antiknock Rating, measure of the ability of a fuel to resist knocking when ignited in a mixture with air in the cylinder of an internal-combustion engine. The octane number is determined by comparing, under standard conditions, the knock intensity of the fuel with that of blends of two reference fuels: iso-octane, which resists knocking, and heptane, which knocks readily. The octane number is the percentage by volume of iso-octane in the iso-octane–heptane mixture that matches the fuel being tested in a standard test engine.
The octane number of a fuel is measured in a test engine against a mixture of iso-octane and heptane. If a gasoline sample has the same antiknock quality as that of a mixture containing 90% isooctane and 10% heptane, then the octane number for that sample is defined as 90. Some hydrocarbons have higher anti-knocking capacity than iso-octane. Hence, octane number definition is extended to allow octane numbers higher than 100.