2007 2500 CTD Mileage

We just came back from our 3600 KM (2235 mile) round trip to Winnipeg.
We have a new 2500 2007 RAM quad cab with the 5.9 CTD. We are towing a 25' Road Ranger 252T travel trailer weighing in at around 8600 lbs. We started
the trip with about 2366 km (1470 mi) on the odometer. The TT is pretty well a solid wall going 100 KM / hour (62 mph) with very little for aerodynamics.
We averaged 13.5 MPG (17.42 l/100 km) on the way out with no wind, but got down to 11.5 MPG (20.45 l/ 100 km) on the way back with a 30 KM (18 mph) head wind. We pretty well stayed at 110KPH (68 mph) on the highway in tow/haul mode.(I love the new automatic tow/haul mode)
We did get around 17.5 MPG (13.44 l/100 km) running around the city without the trailer. We now have 5957 km on the odometer.
What is a realistic expectation for mileage? Is 13.5 mpg normal? or am I just too impatient as it is still getting broke in?
I have seen different people on the group say they get 15 MPG (15.68 l/100 km) towing their trailers. I am pretty sure it will get better.(I hope). Don't get me wrong, this thing beats the heck out of my 2004 5.7 hemi. It got 6.5 MPG pulling the same trailer.
Either way, I can never go back now that I have gone over to diesel.
Wayne
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Wayne, I don't haul with my dually, but with 4.11 gears I first got 15.4 mpg at sustained speed of 100 kph. I now have 27,000 miles on the clock and I generally see 18+ MPG. I have seen 19.3 over 1 tank of fuel. Mileage starts dropping dramatically past 80 KPH, but that is probably due to the 4.11s. The ideal engine speed for economy is 1850 RPM and 600 F degrees EGT. Steve

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Wayne
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