This article is from the Gasoline FAQ, by Bruce Hamilton with numerous contributions by others.
Gasolines are usually defined by government regulation, where properties and
test methods are clearly defined. In the US, several government and state
bodies can specify gasoline properties, and they may choose to use or modify
consensus minimum quality standards, such as American Society for Testing
Materials (ASTM). The US gasoline specifications and test methods are listed
in several readily available publications, including the Society of
Automotive Engineers (SAE) , and the Annual Book of ASTM Standards .
The 1995 ASTM edition includes:-
D4814-94d Specification for Automotive Spark-Ignition Engine Fuel.
This specification lists various properties that all fuels have to comply
with, and may be updated throughout the year. Typical properties are:-