Well, I am leveled out at about 13 mpg on E85. That's mostly back country road driving. 12' Denali xl 4wd. At $2.05/gallon recently, I'm not upset at all with that. The Shell stations around here have 89 octane, and 93 octane. Man the 93 is really spendy! I'm not supposed to run less than 91 in my 6.2L. So E85 has been a great option!