Based on an unscientific survey of pump prices, the annual cost of E85 versus E10 fuel for a 2013 Dodge Ram is 1.33% more.
The EPA combined fuel efficiency is 16 MPG for gasoline and 11 MPG for E85. That’s a ratio of 1.45:1. Pump prices were $3.67/gal for gasoline (E10) and $3.29/gal for E85. That makes the cost of fuel 1.33% more for E85. Sounds like a great deal. At 10k miles per year, the additional fuel cost for E85 is $750. I pass.