Hi all want to get it right the first time I've heard differant #'s for best working rpm but that may be unloaded I'll be yanking 14000lbs Now tq gets you goin and that starts strong and climbs from 1500 unward and I think ,correct me if I'm wrong decent hp #'s at 1900 and some place is the magic overlap and I think gear ratio has something to do with it no maybe thats to maintian speed at magic rpm please help signed don't want to hurt my ctd . note: HO 6 speed no engine mods [yet]. 3:55 gears

 

My 24v loves 2200rpm. It runs strong at 1800, and very strong at 2000, but 2200 is definately the sweet spot. As for getting the load rolling, 1800 and up. Max rpm depends on the grade. Just getting a 14,000# trailer up to speed, probably 2700 at shift. On a steep grade, 3000-3200. I have some mods and an auto, so I hope this helps.

 

These Cummins' have a pretty broad powerband.

On my truck 1900 thru 2500 RPMs is where it likes to be, and I use the 6 speed to keep it in the sweet spot.

 

You're probably near the same HP numbers as my '03 SO.

I pull 10-11K with the 48RE, 4:10 gears.

To maintain momentum in the mountains and on the flat lands, I like to stay in the 2000 - 2500 RPM range, although on the steepest grades I'll run it hard at 2900-3000 RPM

Towing for me is more about maintaining momentum, not necesarrily speed. On flat highway, I run 70 MPH at 2000-2200 RPM

 

Run in OD until the rpms drop below 2000 (1900, 1800) then down shift until you do not have to keep it on the floor climbing the grade. Doing it this way, the temps will stay down, EGT's down, economy better, the load on the drive line is less. I like to downshift until the rpm's will hold at 2500 or 2600 at part throttle. This is also Cummins recommendation, to go up a grade in a gear that you can accelerate. It is hard to keep from drag racing up the hills but a lot easier on the truck doing it right.

 

Cummins Power Boosters put out a newsletter several years ago...

It stated that for the 24 valve, best mileage was to be had at 1800-2000rpm, and the best power for towing was at 2000-2200rpm.

I have used that info, and it has served me well. I am sure they did some testing to find those numbers.

 

I have 33" wheels/tires and 3.73s. I run 2000 @ 75 MPH... I need 4.10's to kick that 2000 up to about 2200 RPM.

 

It would handle rolling hills better with the 2200. I am 2100 at 75 and it is ok.