I had to go to Austin today to take some stuff up to my son. I knew I was going to need fuel before I came back so I waited till I got there and filled up on the way back with E85. Since the truck is flex fuel, I've been curious. Here are my preliminary observations. At the HEB there in Austin, E85 was $2.87/gal compared to $3.27/gal for regular gas. This comes out to a 12.23% favorable difference in price. The truck still had some regular gas in it, about 6 gallons. The truck took 25 gallons to fill it up. Based on the auto MPG calculation by the truck, I was averaging 15.3 mpg on the last tank of gas. I had covered about 360 miles on this tank and this included a trip up and back from Austin, the trip up this morning, a trip to work Monday (about 60 miles round trip) and some driving around San Antonio. So far, the truck is showing 12.6 mpg on the trip back from Austin, a decrease of 17.6%. This calculates out to I covered the same route coming back that I did this earlier in the day (US 281 to US 290 and up Loop road 1). The temperature coming back might have been 3 or 4 degrees higher (mid 90s). I'm going to run the tank on down and then check the final mileage. Right now, it looks like the decreased mileage is not being offset by the decreased cost. I'm figuring that since I still had some regular gas (E10) in the tank that the mileage right now might be a little better than with straight E85. I wanted to check this out before I move back to WV as E85 is not readily available there. Others may have different experience but this is what I'm seeing so far.