ISO 5164 - Research Octane Number
We perform gasoline testing by ISO 5164 to find the research Octane Number, which is combined with ISO 5163 to define the antiknock index of gasoline. Research Octane Number correlates with commercial automotive spark-ignition engine antiknock performance under mild conditions of operation. Research Octane Number, in conjunction with Motor Octane Number (ISO 5163), defines the antiknock index of automotive spark-ignition engine fuels, in accordance with Specification ASTM D4814. The antiknock index of a fuel approximates the Road octane ratings for many vehicles, is posted on retail dispensing pumps in the U.S., and is referred to in vehicle manuals.
You can learn more about this test standard, or purchase a copy, by going to the website for ISO - the International Organization for Standardization.