So I finally am going to use my e30 tune, there is only one station relatively close to me w/e85 so I have not had the ambition to do it yet. Went today and filled a 14 gallon gas can with 3.4 gal e85 and 9.6 gal of regular 93 for 13 gallons of e30....so I thought. I grabbed and extra can and put another gallon of e85 in it just in case. Being the paranoid type I bought an ethanol tester because I wanted to be sure, ummm how about e15!! I then checked the straight e85 and it measures e55!!! WTF? I know it will not always be perfectly e85 but that just seems ridiculous to me. I took out 3 gallons from the big can and added the remaining gallon of e85 and now I'm at e20 or so. I'm kind of pissed but very relieved I did not just fill up and hope for the best. I guess back to the station for another 5 gallons and custom mixing.