You're not the only crazy person here, I have the same truck in 2WD.
http://ecomodder.com/forum/showthrea...0hd-32970.html I'm mainly doing aeromods, though parts will be replaced with more efficient ones as they fail, if available. I was on vacation for the last month, so I haven't put many miles on it with the mods I've done so far. Stock I would get about 13MPG in mixed driving, about 14MPG doing 75MPH, and 16MPG doing about 60MPH.