We just returned from Beaufort after a 5 day 1200 mile round trip in the R/T AWD towing our 18' trailer. Trailer probably weighed around 3300# loaded up, possibly more. My wife can stuff a trailer.
The Good:
-DD very competent tow vehicle
-Plenty of power
-Very comfortable
-AWD backed trailer up gravel hills without drama
The Bad:
-Mileage, rather poor when compared to my 2012 4 Runner (11.3 vs 12.5)
-Volant a bit noisy when towing

4Runner struggled pulling so I had to downshift to 4th or even 3rd in order to get enough juice to pull my "brick", yet it did better in mpg. Odd. Durango overall a very good tow vehicle

 

Depending on where you are towing (hills, flat or???) Lets just say 4000lbs. That really isnt bad mileage at all.
Plus you were probably able to maintain speed easier and higher thus the comparison is mute
Enjoy your new D and never look back
STEVE

 

Did you use TOW/Haul mode on the interstate? Some guys turn it off when they reach cruise 55-60 mph and on flat road can get MDS to work towing with that weight. That could pop you another mpg or 2. Also next trip try if you can't get MDS to stay on try using 5th gear instead of 6th. you will run a couple hundred RPMs higher but the engine will be under less load in that gear possibly improving mileage. Experiment with speed and variety. Car and driver was able to squeeze an extra 2 mpg with there long term 09' ram experimenting with some of these while towing race cars across country.

 

There were stretches where I could take it out of tow/haul mode and take advantage of the MDS. We were in hills and flat country. I figured I might pull 12 mpg out of the beast, but the way it tows makes me not mind taking the hit in mpg......I am quite enjoying this vehicle. Stable as a train on rails!

 

Nice. My towing experience with the D was great as well. Long moving trailer full of crap, was easy as pie. Made me want to find heavier stuff to pull.

 

I tow my 5,000 lb Airstream and haven't used tow/haul. The only time I might use it would be out west towing in real mountains. I get about 12 mpg, same as my ML500 got.

 

I monitored my trans temp and found that Tow/Haul mode tended to keep the trans cooler. It seemed to stay around 164 degrees. If I let it hunt too much I saw the temp rise to 188. Going back to T/H mode brought temps back in line. I love that the DD has extensive systems monitoring.

 

Even 188 isn't bad when Towing but 164 is surely better.
STEVE

 

Steve, someone once posted a transmission fluid life vs. temperature chart on the 4Runner forum and it was pretty amazing how much fluid life was shortened when temps exceeded 210-220. Actually 188 was decent as I was in traffic and it was warm in Atlanta.

 

Yep. Tow / Haul will extend transmission life while towing. Keeping those cluth packs alive. Only if I can... I.e flat or downhill will I switch out and take advantage of MDS. Mostly I'm in manual mode holding my chosen gear anyways. Next year I'm towing the camaro up to Auto Cub Speedway that will be 4000+ lbs with tires and gear. Lots of fun