Well, I thought I'd chime in on the debate between the big three trucks. I have a small transport company and we are currently hauling RV campers down south to MI & LA.
I have hired on a few trucks and we have run together on some of these trips. My truck's specs are below, Other trucks have been the GMC Duramax & both the 7.whatever & the 6.0 PowerStrokers and an older Dodge 6spd.
We all agree to run Cruise-Control set at 80 m.p.h. from Tenn. down, yet every hill when I'm in the lead, my truck pulls the hill and gains on the others. Within a half hour I'm at least 4 - 5 miles ahead of the others. When I try to follow them, I constantly have to go off Cruise. Fuel mileage - I average 11.5 to 12.5 mpg loaded, running at 80 m.p.h. The others tell me what they get for fuel mileage but they usually need to stop before me. So their mileage - not as good as mine!!
I also want to mention that all of the hired trucks have the taller?? gears like 3:73 or 3:53. I have often wondered about changing from my 4:10's but no longer even consider it.
Cummins - just can't be beat!! 136K on the clock and climbing fast.

 

I would think cruise at 80mph is not a realistic speed for a mixed diesel truck convoy pulling high profile loads. I would guess that at that speed a lot of trucks are out of optimum torque ranges, etc. Along with the fact that you gotta be wasting a ton of money on fuel. Since you gotta do the "slinky" convoy, I would drop down to the speed limit and eliminate a lot of slinky action and save a bunch of money. Probably wouldn't loose that much time either. Just my .02.

 

That's what I have been trying to tell guys for years. If you tow alot the 4:10's are the only way to go, especially with the auto trans.

11.5-12.5 doing 80 MPH pulling camper is spectacular mileage, I'am jealous, I only get 10-11 pulling a 147 inch tall 12,000 lb 5th wheel at 70 MPH. I still concider it good though.

 

just remember the dura`s have a small tank on the truck,,not sure on what all of you are using as auxillary tanks.the duras i know get just as good of mileage as my 05,,the powerstrokes,,well,thats just not worth discussing there................gotta love that cummins dont ya?,,,,,,,,,,bama

 

"my truck pulls the hill and gains on the others. Within a half hour I'm at least 4 - 5 miles ahead of the others."

That is what I said the Cummins would do compared to the others in a discussion about how fast the Duramax was in a drag race on this forum.

I think the Cummins builds boost <way> slower than the 6.0 and Duramax and thus they will win the drag races. Frankly I could care less. Once the Cummins builds boost, it rocks.

I drive a 6 speed and pull 32 feet of 5er weighing nearly 10,000 pounds in the mountains.

The Cummins pulls very well, the best I've ever felt in a diesel pickup. It gets outstanding fuel economy and it is tough as nails. And it is simple to work on, especially compared to the others. What more could one want ?

BTW: I have to admit those Mega cabs look great. Recently I've thought that I maybe should have waited and bought one rather than doing my conversion. Then again my Ford works great and I don't have a truck payment to worry about.