It's the fuel of the future, because we grow it. The Ridgeline service manual says:
Normal Driving: Unleaded gasoline with 86 pump octane number or higher
Towing: Towing performance can be affected by high altitude, high temperature, or when climbing steep grades. Therefore, premium fuel is recommended when towing more than 3500 lbs (1590 kg).
Found on Owner Link:
Fuels that exceed the EPA's approved oxygenate percentages for conventional and reformulated gasolines must be clearly labeled on the pump. One example of such a fuel is "E85," which contains 85% ethanol. Do not use such fuels in your vehicle. These fuels will cause performance problems, and may damage your vehicle's engine, fuel system, and emission control system. This damage would not be covered under warranty.
Guess not.