Im looking at an 04 3/4 ton with a Duramax. 95k. Its one of our sales guys. The problem is it gets 13.5 mpg, on paper and electronically. I know of 3 other 2/4wd 3/4 tons that get 18-22. Our one ton duallys at work only get 11-12 but they are both at 18k.
I have put Rotella T in it, and besides a programmer etc what else could be the problem.
Karl, DavidO?