x2 + shorter engine life and other problems due to the inefficient higher octane fuel. Is the E85 even cheaper, if so it is only because of government subsidies because the corn costs more than the crude - my dad work in the bio-fuels division at Chevron for six years
. I'm not a big fan of E85, but bio-diesel that stuff is a different story that is a good product. I would suggest trying to make your truck more efficient rather than a fuel system switch. For example, invest in a new intake, exhaust, chip/programmer, and throttle body.