All I will say is I have a 2007 2500 4wd QC with the 6.7 all stock with no mods whatsoever. I tow my 28ft trailer with car, tools, generator, 4 wheeler and all other kinds of items and I get anywhere from 10.5 to 12.5 mpg depending on speed. Over 70 is the worst and if I stay around 60/65 I get the best.


I'm quite content with these numbers and not spending any $$$$ to try and save a couple MPG. The ROI will never materialize if I did add anything.