This is interesting. I live at 10,000 feet elevation near Breckenridge Colorado and plow often. With daily freeze/thaw cycles and lots of sun shine, here is the cardinal rule: Never ever drive over your driveway with snow on it. The result tracks become ice after a few cycles and you will...
Everyone's mileage varies. The E85 costing about 32% less than mid-range, delivers 12% less mileage at altitude (8-10,000 feet). Other mixes? Sure, mix your own at the pump. Try it and let us know.