[rgrmoreira13]

Originally Posted by Vanishing Point

I have moved to Dallas about a year and a half ago and have had a hard time finding a decent builder/tuner. There are too many issues to mention, but one interesting question I figured was a quick answer for you guys. One shop said for E85 flex (run it on E85 usually and premium gasoline when E85 is not available), it requires 2 tunes, one for gas, one for E85. The next shop said no, just one tune on E85 and the car’s computer will figure it out for the gasoline adjustment. Keep in mind some other changes were occurring which would necessitate a full retuning so it wasn’t just the addition of E85 to consider. The first one (dual tune) seems to make the most sense, but they were shady as hell so it might have just been a way to double the tuning charges. So is it 1 or 2 tunes required? Thanks.

Well no.
You will need to get the car tuned to receive E85. However your tuner will have the parameters to change the timing if your E85 content reaches a certain percentages. Because even if you run pure 93 it will still have some Ethanol in the gas and will have around 10% of E. so yea I would honestly go with your second tuner.