I have to eat my words on my 15 Rammit. It has the high gears, 6 speed and around town it is a bit gutless. I didn't think it had the guts to tow a trailer but I was wrong.
We have a hill heading out of my old town that is 8% and runs for around 10 miles. I loaded this mother down with my 4000lb Stealth in the back of the 26 ft trailer and around 2500lbs in the front of the trailer and the back of the truck. She buzzed up that hill just fine at 50MPH. She would have pulled up there faster but I kept the revs to around 3500 and she held it just fine.
And guess what else? On the 500 mile trip she got 9MPG overall, which is maybe 1 to 2 MPG less than my old 05 Cummins would have done.
I don't think you need a gear change with your ecodiesel but that's just my opinion. My truck is not optioned optimally to pull but it does it just fine.
My truck came with 17's and I switched to the 20's tire circumference is 5% larger than the 17's.

It has the high gears, 6 speed
? I assume were talking 3.90's rear gear?

factory 20" tires on the 4x4's are 33" tall, the 275/60/20 thats why most come with a 3.9 gear due to the 33" height. 3.55s are too high for 33's. the newer trucks with the 6 or 8 speed trannies can get away with the higher gears

Mine has 3.55. As I said it is totally the non optimal setup for towing and it kicked azz anyway. 1500, six speed, 3.55, 20 inch wheels and pulling about 11,000lbs over a 10 mile long 8 percent grade. I can't call it my girly truck anymore.

I figured you would come around and like your new truck sometime.

Little update on my '01 360 Mag above:

Towed a '98 QC 4x4 (5500lbs) on a heavier trailer (2500lbs) and started the trip at 10.5mpg and by the time I got home (350 miles) the average wound up at 13.0mpg

45 to 55mph in third on all the mean hills and stayed in top gear on the level at 60mph.

Nope, still don't miss my old '02 Cummins.

Any ideal what transmission in the 2000-03 rams?46r or what tranny?

46 RE until 03, they made some changes

Any ideal what changes ,did they go 5 speed?Thaxs.....

The 03 Ram with the Hemi we parted out had a 5 speed auto. Have no idea if it was an option, or an across the board change, or a Hemi deal.
Gene

Our 09 ram r/t. (They only come with 4.10 gears) 5 speed Auto. I towed Mt open 23 steel floor trailer 71 charger down to ar. Other then bumps never it was back there and I never turned the overdrive off 75-80 most the way. Was just like normal driving (under 2k on the tach) truck also had 20" wheels