Since I got my fifth wheel in now drive without the overdrive. What sort of RPM is good for a long drive. I use to run about 2k doing 70+ now I run 2300 doing 60.

-Pete

 

That sounds about right. I think that the economical RPM is anywhere from 1900-2220, unloaded. With that 5th wheel, that sounds like it should raise up your rpm. If at all possible, try and keep your rpm below 2200, if posible. I guess it depends on driving conditions like hills and what not. Just my $.02.

Hunter

 

With 4.10 gears, my truck runs 2350 RPM @ 70 MPH in 6th gear. We pull a 13,500 lb 5th wheel, and I'll run all day on the Interstates at 70-75 MPH (2350 - 2500 RPM) without overheating, using any oil, etc. You're not going to hurt the engine running 2200 - 2300 RPM. Now, hurting your wallet when it's time to fuel up may be another matter.....

Rusty

 

Have towed all day long in third gear at 2600rpm. It won't hurt the Cummins at all. But as said above, it will hurt the mileage and the pocketbook!

 

When you are towing, your best mileage is going to be between 2000 and 2200 RPMs, with a second gen engine. Many here have found that to be the sweet spot under load. With my 4:10 gears and in OD, I run 65 mph at 2100 or so, and I can pull there all day long. (11K pound fiver)

 

Everything I have read on this, and other sites, says the automatic transmission in my year truck (2000) is it's weakest point. The truck is rated to pull 9900 lbs and the 5th is around 12k lbs. Until I can get an ATS transmission installed it was recommended to drive w/o overdrive.

-Pete

 

Guys, I pull a 10K fiver all day long in drive around 2200 rpm at 62 mph with no problem. My mileage varies between 10 & 12 mpg, DTT told me to keep the rpms up to maintain high line pressure which will help keep the stock tyranny alive. I don't want to become my own warranty station and leave Dodge off the hook. Diesel is quite a bit cheaper than a new aftermarket tyranny.

 

You can run that ISB right up to the governor all day long it will hurt the pocket book in mileage, but not the motor. these ISB in midrange truck run all day long against the governor all day long , just keep an eye on the temperatures.

 

Yep, but I don't think in the medium dutys they govern them at 3250 do they????

That's pretty screamin'

 

The medium duties are governed at 2500 or 2600. The engine is the same except for the cam.