Greg; I'm running 11.2-1, I'd like to have had 12.5-13-1. The motor was junk off the garage floor and I didn't want to spend any money on it. 11.2-1 was as much as I safey dared squeeze it without having valves poking holes in the pistons.
As far as mileage goes, the last time I drove it going to the strip I was bucking a 25 mph headwind on the way down there. My mileage was 9.5 mpg, 1 mpg less than the last time I checked it on gasoline. I think it is probably as good or better than when the motor was on gasoline. I do believe most of the mileage issue can be made up by bumping the compression up as high as possible. Another point, I'm running it quite a bit on the rich side, for max power, I could lean the mixture down about 7%.
I haven't run it at the strip on E-85 but it feels as strong, or stronger on E-85 than it did on gasoline. Here's an example;
Last fall my brother and a buddy of his stopped by one Sunday. I was tuning on the carb. They decided I should take them for a ride. So the 3 of us piled into the truck, (650lbs.) I had the street tires and full exhaust on and the caltracks. We went east on a good hooking new asphalt road. I stood on it at 40-45mph. The rearend started to come around on me, we were at a 45 degree angle before it finally hooked up again. On gasoline it never did that before at least not at 80 degree temps.Dave