auto and 4.10's. if your easy with her you can see probably 17, however a more realistic number may be around 15. You RPM's running at 70 will be around 21-2200rpm which is high, but not like the manual. The 4.10's will help relieve alot of drive train strain, but the amazing thing is the 3.73's will also do good and I know plenty of guys that run 3.73's pulling 35+foot 5vr campers without a problem.

drive both the 4.10's and 3.73's and see what you think. also while testing them hit the tow haul and see where the RPM's go when running the speed-o to 60mph. I'm realy on the fence of what to truly tell you as to what would be best. the 4.10's will help when towing, however if you dont realy tow but maybe once or twice a month the 3.73's will be better for when your putting around town.

 

Again, thanks for the info. Sorry for all the questions. I'll take your advice and drive both.

 

Hey guys is or would it be bad for me to run my 06 cummins with a six speed at 80 MPH? I think it is running like 2500 to 2700 RPMs at 80 mph. I know it will be tuff on fuel but will it be tuff on the truck too?

 

I wouldn't think so. I would have to believe that these engines were made for running, but I'm probably not the right guy to be answerig that. What kind of fuel mileage are you getting? How do you like your CTD?

 

I have a 2005 CD 4x4 mega cab, auto, 3.73, series 2500, mileage about 21 K so it is not truly comparable to your 1 ton series. But for what it is worth:
There is a mile long hill nearby that will cause a number of cars to kick out of overdrive because of the grade. The other day I whipped up the hill at 65 plus pulling a 10,000 lb. travel trailer and that silly truck never kicked down and hardly lost any mph.
I often pull a 24 foot flatbed gooseneck (weight 4,000) with a 9 or 10 K load. I try to stay at around 70 mph and rarely does the truck ever kick out of overdrive. Last Sat. I drove just the truck 789 miles, 90 to 100 air temp, A/C on, pretty constant 73 mph, Drews brew and averaged 17.07 mpg. For a 7,000 lb. truck that seems pretty good to me.

As to your choice of stick or auto. With the modern auto and a bit of servicing, you will probably have less strain and drivetrain expense over 200,000 miles than you would with a stick shift. Also, with an engine developing as much torque as the Cummins, and modern automatic transmissions, it would probably be hard to measure any increase in fuel usage.

As you may note from other postings on the board, the 4:10 choice makes for more engine rpm/noise. If you drive for 8 or 12 hour stretches you may not care for the additional noise.

Whatever combo you choose, welcome to the world of DCD

 

Thanks Barry KC.

 

Barry KC, have you had any issues with your auto? or the truck in general?

 

as far as engine RPM's go, these things can run 2500-3000 all day long and into next week without any issues. your fuel consumption will be very high, but it can do it.

 

No, I have had no problems or even petty little irritations (as I did with the Silverados). The one exception is that the A/C needs to be looked at by the dealer because the cold air is about kaput if driving below 40 mph. Perhaps gas, valving, or ?, but I'll let the dealer play because it should be under warranty.
Let us know what you decide to buy.
PS - just had a thought!!!! The metal deck that is offered for the back seat area is worth it's weight in gold. I never knew it would be so useful. We even made a deck out of it for our 100 pound dog using big cushions. She stretches out back there and thinks she is in heaven.
You may find it a wothwhile option.

 

did you own a Silverado w/ the Druamax?