Octane rating facts for kids
The rating is done by comparing the fuel to the mixture of iso-octane and heptane that would detonate in the same way. Such a mixture of 90 percent iso-octane and 10 percent heptane has an octane rating of 90.
Gas is available with lower octane ratings in the US than in Europe.
Images for kids
Octane rating Facts for Kids. Kiddle Encyclopedia.