I towed our Jeep 3,300 miles through every type of terrain and averaged about 12 MPG. My 1500 with the 5.7 averaged about 9 towing the same Jeep on the reverse of that trip (West to East). I just got my best tank (unloaded) making a run out to Vegas recently and that averaged 16.1 MPG. People love criticizing the mileage, but show me a LC100 or similar do better once you have it rigged for off-road.
I wasn't criticizing the fuel economy, but it is what it is. We can caveat that with exceptions for modifications and towing, ect., but comparing stock to stock, the 6.4l 2500 has lower fuel economy compared to others....that's all I'm saying.