I am so sorry, but I am truly ignorant on E85 fuel, how it works, and what cars can run it.
I have a 2014 GT with the FRPP TrackKey and I currently run 91-93 octane pump gas (depending on the station I fill up at).
The other day I had to stop and fuel up my "company" car on my way to work at a gas station I hadn't been to in a long while. I noticed they had new pumps and they had a separate fuel nozzle for ethanol fuel. It was a Texaco, and the buttons had a brand label that was something like MexiFuel, not a Texaco product, minimum 70% ethanol, E104. (There were two ethanol choices side by side actually, one might have read E85, and the other E104.)
If nothing in what I've typed so far sounded ignorant, then my questions here is were the really ignorant stuff starts...
With E85, do you have to run an E85 specific tune and injectors? E85 wont work in a stock Mustang will it? If it does, would one see an increase in performance running E104? Am I right to assume E104 is basically a 104 octane fuel? Would one need to be running a tune to see any increase in performance running the E104? If you're tuned for ethanol, can you run pump gas in a pinch?
School this ignorant person! (Gently please!