Well, just gave the ole Dodge the first REAL workout it's ever had.
Just completed a trip from Seattle to Anchorage with a newly acquired camper and utility trailer. Best guess is truck and trailer were grossing about 18k lbs. Not alot until you consider the the truck was packin about 13k of it!
Put on a set of airbags and a BD brake, pumped up the rear Toyos to 80lbs and let 'er rip.
Only thing keeping it from reaching terminal velocity was the Winnebago humpin the back of the truck and egts! Coulda pulled the whole trip in 6th gear with throttle to spare if I didnt want to keep the temps below 1200.
Took a pretty good beatin on the suspension and driveline over hundreds of miles of frost heaves too.
Truck ran like an absolute champ with a little over 100k mi on it the entire way. Averaged 11.5mpg to boot and that was runnin 65-70mph whenever possible (not very much maybe 20% of the time).

 

Nice to hear!! That does sound like a pretty good workout for the Cummins Mega!!

 

I imagine the truck liked the workout. I hear they do well when they get worked.

Do you plan to upgrade to bags or the suspension for any future trips with the camper?

 

I put Firestone bags on it already. That camper would have buried the back of the truck otherwise. Only thing I need to do is make some blocks or wedges like the Stable Loads that engage the overload leaf (bottom leaf on a 2500) when I have the bags pumped back up to normal ride height.
That will eliminate some of the body roll.

Tires are rated to 3950lbs IIRC although not ideal for hauling that weight since they're a siped mud terrain tire. I put about 10,000miles of wear on the rear tires in under 2000miles of driving.

I can see the benefit of a dually for stability, but I think most of the body roll comes from not sitting hard on a stiff overload spring.

Even with top quality tiedowns and a rubber bed mat to prevent sliding and shifting, the camper put a little hurtin on the bed. Dented the front of the bed, inside just a bit and smashed couple flat spots into the one rib on the tailgate.
Actually had ALOT of weight on the tailgate. Cables were like a banjo string. Didn't realize it, but dumb design on Dodge's part, the tailgate actually sits almost 1/2" higher than the bed floor when it's laying down flat. Even with the 1/4" bed mat in the bed, there was a small gap between the back of the bed and the bottom of the camper.
I wanted that extra stability for the 2' of camper hanging off the bed but need to"shim" up under the bed mat with some 1/4" plywood or another mat so the tailgate isn't taking all the weight, rather just controlling any flex in the back part of the camper chassis.

 

Engine needed a good workout. Got some mpgs back. Other than towing a 3 place sled trailer around in the winter and boat to the lake occasionally it hasn't worked at all in 2+ years.
Empty mpg's were down in the 16's on the overhead pre trip.
Now close to 18mpg again.

Still impressed with the mpg on the trip. Same drive a month ago with a new F250 6.2L gasser with less than 1000lbs in the bed and about a 4000lb single axle trailer on 245 street tires only got 8mpg versus over 11 on the diesel with a whole lot more weight and wind resistance.
Same hills that I was pulling in 5th gear at 1000deg egt or less in the Dodge were 3rd or sometimes 2nd gear pulls wound up in the Ferd.