how will ethanol affect my fuel mileage ?

I have an 04 ram with a hemi. I avoid ethanol like it's the plague! 10% in regular gas cuts my mileage by 10-15%. The truck doesn't run as well either. In the long run you would be better off running ethanol free all together. We have couple stations here that ethanol free. I have a 99 Toyota corolla that gets 5 miles to the gallon better on ethanol free!