E85 has a different stoich than 93 premium or 100 octane Sunoco 260GT. If you add E85 without changing your tune, the car will run lean.
You can't rely upon the AFR gauge if you have it in your gauge package to warn you since it is calibrated for normal fuel (0-10% ethanol).
You can't rely upon the AFR gauge if you have it in your gauge package to warn you since it is calibrated for normal fuel (0-10% ethanol).