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.
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2,2,4-Trimethylpentane (iso-octane) (upper) has an octane rating of 100 whereas n-heptane has an octane rating of 0.
Octane rating Facts for Kids. Kiddle Encyclopedia.