E10 is not available here but there is E85. I thought that I would test and see the effects of a mixture of E15 made from the E85. After looking at http://www.ethanol.org/documents/ACE...onomyStudy.pdf
It looks like on small displacement engine there is not much of a decrease with E10 and only a 2% with E20 so I thought I try E15 to see if I could find the sweet spot.
I did three bi-directional runs over a 2 mile course with the cruise control set at 60 MPH. Weather was 89 with winds out of the southwest at 15mph at the begining of the runs and the temp climbed to 90 at the end of the run. After completion of the first 3 runs there was 7 gallons remaining. I added 1.5 gallons of E85 which if my math is correct means that there were 8.5 gallons total with 1.3 gallons of ethanol bringing the mixture to 15%. After reseting the ECU and driving around for 20 minutes to give it time to adjust I completed 3 more bi-directional runs.
Average of runs with straight gasoline 39.35 MPG
Average of runs with E15 39.57 MPG
So with the E15 mix it was a break even deal FE wise. Cost of the E85 is $0.30 cheaper than regular 87. Your mileage may vary.