I am not bragging, just posting what the computer says for information sake. My Cummins is a 2004, completely stock with 200K on it. I currently tow a Denali trailer that weighs about 7500# loaded. I have not been to the scales yet, but that is a pretty good guess. I have made two long trips, I tow at about 63 mph, in OD, and I am getting about 15 mpg. When I had my much larger Mobile Scout trailer which weighed in at 11K I was getting about 13.5 mpg.
I have had this trk 10 years and I put 20k a year on it which is about 5k towing miles. It would be really hard to complain about the service I have gotten at this point.
Dave and Anita
2015 Itasca Sunova 33C