Re: 07 F150 Fuel Gauge reads --- ???
I'll guess here and say that the E85 is causing the sending unit in the tank to 'stick'. E85 is primarily made from corn, and is starchy, along with several other oils. You'll have to get the engine code scanned to better narrow down the problem. If there's an Autozone around, they'll scan for free - last I checked. Having to replacing the sending unit/pump in the tank (guage is probably OK), could run between $200-400 depending on parts (new or used) and shop labour.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!