Thats interesting since all the current tunes already address ethanol up to E25. Maybe they are behind the times and just hadn't downloaded new tunes for the Tbird for a while. In any event i'd love to try it, but at this point my bike is running so amazingly i doubt i will chance doing ANYTHING that might change that. Do me a favor if you can...ask them what the tune number is. I want to see if it's different than mine.