My daughters 2017 F250 6.2 has been a great tow vehicle. Absolulity 0 problems with the truck. Not to beat a dead horse on the E85 but this is from Fords manual
"Switching Between E85 and Gasoline
We do not recommend repeatedly alternating between E85 and gasoline. If you switch from using E85 to gasoline, or from gasoline to E85, add as much fuel as possible, at least half a tank. Drive your vehicle immediately for a minimum of 5 mi (8 km) to allow it to adapt to the change in ethanol concentration. If you use E85 exclusively, we recommend that you fill the fuel tank with regular unleaded gasoline at each scheduled oil change."