$5 a gallon for gas?

[Cutty72]

first, yes, lower octane in higher elevations. ie my cousin lives in utah, they have 85, 88, and 91 octane.

E85 is 105 octane
E85 is also a lot cheaper, but you will burn more.
A vehicle that gets 25 mpg buring 89 octane fuel, will get about 18 mpg under the same conditions burning E85.

A lot of hot rodders and racers to retune the cars to run E85, as the loss in efficiency for them is not that big of deal.