Well I read all this and some other threads on here. I went and and bought 8 gal of E85 to mix with the almost 8 Gallons of Shell 93. Drove for 10 miles. Then on the freeway opened her up. I didn't notice to much in performance, but since 93 was $2.89 a gallon and E85 was $2.34 I noticed a savings. I drove the rest of the way home, no cell lights not hesitation I even stopped by the local dealer to talke a look at the new 06 STI in person and then drove home. I have put 35 miles on the car in 93 degree heat and it is doing just fine. This is an 05 Cobb STG 1 STI. I am eager to see how many miles I can get out of the tank to see if I am really saving $4 a fill up. Thanks Hotrod for posting such valuable info!