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M85 has an octane rating of 102, compared to 87 for most regular unleaded gasoline. This higher octane rating provides superior anti-knock properties for high-performance engines with high compression ratios.

M85 contains 59 percent as much energy per gallon as gasoline (66,350 Btu per gallon of M85, compared to 111,800 Btu for gasoline). This lower energy density reduces the range that a given vehicle can travel on the same size tank of fuel.