Last 3 tanks in the Stratus on E10 34.75 mpg, 3 tanks before that on E0 34.63 mpg. pratically the same. I'll go back to E0 next three tanks to see if I can do better as my driving is still improving slightly.
I've played with other blends in the spring, but other variables with the car caused that data to have limited value.
Some studies show MPG actauly going up with E10
http://www.ethanol.org/pdf/contentmg...yStudy_001.pdf
There's another one I've found before where IIRC 3 of the 4 cars went up by a small amount, only a Nissan Versa went down by 3% or so pulling the average down to basically same E0 or E10. But can't find it now.