I know this is an old thread but just thought I would update on the towing experience this year.
We left Florida and travelled across Alabam, Mississippi, Texas, New Mexico, Arizona and are currently in Utah.
Truck has performed beyond what I had expected. The grade braking on the long down hills has been great. The 18 mile downhill on 17 to Sedona was a piece of cake. Truck stayed right at 60.
Going back up 17, again was a big surprise. No problems at all.
We have hit a couple of 8% grades but the truck revved up to almost 4500 a couple of times but without any complaint.
Transmission and engine temp gauges stayed with the safe range.
Find that if I let the truck do the driving, I am better off. By that I mean leave it in drive and cruise. It knows what to do.
I don't think the 06 2500 could have done much better with the 4 speed. I am really enjoying this truck.
I really thing the 6 speed tranny makes a big difference.
Getting about 10 mpg which is better than the old truck.
Again, thanks for all the help and advice last year.