http://en.wikipedia.org/wiki/E85

 

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and the point of the link? Mustang is not a car that is E85 friendly. Only some of Fords are and even fewer GM vehicles are. If you car can use it, it will either be in teh owners manual or the fuel tank door. E85 will eat the materials used for most injection components these days. DO NOT USE E85 in a Stang you will be replacing more than just FI components after short term use.