OK. I had my first tow with gauges.
I have a few questions. Truck is basicly stock.
I have read that our best torque is made around 1600rpm. I was pulling a small bumper pull camper (6000lbs) into a decent headwind (20mph).
Started viechel off in tow/haul to get going & once up to speed I switch it into OD. RPM's ran around 1600-1700 @ 70mph. Trans stayed in OD & pulled great. But, here is were my gauges came in handy. I was seeing 1100-1200egt's w-around 18-22 boost. Way to hot for my liking. If I would put trans in tow mode & run 67mph @ 2400rpm's, my egts would be around 950-1000. Or if I left it in od & ran 75mph @ 1900rpm's my egt's would run around 1000-1100.
Basicly what I am trying to get at here is. My truck pulled great & ran cooler when I cranked up the RPM's. But my fuel milage sucked.

Does anyone have any advice on egt's & rpm's to run when pulling? Are my numbers on par with what everyone else is seeing? Did the headwind really push the truck??

Thanks, Jeromie

--------------------
2004.5 2500 Black, Laramie-Sport, Quad cab,Short Box, 4x4, 3.73L Nerf&Bed bars, LT315/70R17 BFG
SRT Hood, Overhead mounted ISSPRO Egt,Boost&Trans gauges. Modified fuel tank vent. Bed extender. Modified air box & intake tube.

 

Sounds like you figured it out. Cummins recommends keeping the RPM's around the 1900-2200 mark (not sure on the exact numbers) and they do recommend downshifting when needed to bring up the RPM's and keep the EGT down.

 

OK, I was under the understanding that I would want to be more around the 1600-2k rpm range for best pulling & fuel milage. I got 7-11mpg depending on when I looked @ my overhead. (I did not hand calculate)

One person thought my 315's took me out of my power band. I can't see how that small change in ratio could cause my truck to run so hot.

Thanks, Jeromie

 

With the 315's your final drive ratio is now 3.43. The auto tranny I believe has a 0.69 ratio for OD and with this combination the engine has to work harder to overcome the reduction in mechanical advantage because of the gearing. So at lower RPMs with high fueling and less boost the EGTs will be high.

MikeyB

 

All four of my Cummins powered Rams liked 2100-2300rpm for towing. I liked 1750rpm for in cab quiet but the Cummins liked to make some horsepower with it's healthy torque output. EGT was cooler because more air through the motor at higher rpm to do the same work. Boost was up making the motor more peppy and ready for hills. My '98 5spd/4.10 ran 2500rpm in O/D at 70mph. I didn't have a choice but to run high rpm. It was unstoppable for 89k miles when I couldn't take the noise anymore and traded for another auto/3.55 to lumber along at 1750rpm bogging down on the hills. The '03 auto/4.10 put the rpm just right on the interstate towing. 2100-2300rpm.

 

04.5 dually with auto 4:10 gears, I pull a 40 ft enclosed usally 75 mph on the interstate. Egt temps vary on alt and grade. I see higher egt with higher rpms. 80 mph is a little over 2400 and it runs great there. I have a edge attitude/w Juice and usally use the tow mode. Last week pulling about 20000 max egt was 1200 and the probe is before the turbo....

 

Am I stuck with this problem w-315's?? Is their anything other than changing gears that I can do to help. I really like the look w-315's

Later, Jeromie

 

unfortunately, I don't think there is nothing you can do, other than re-gear or go to a smaller tire. I've heard on these boards, that the Cummins works best in the 1800-1900 RPM range. Because of the increased height of your tires, your RPM will decrease as well. And when your RPM's decrease, so will the airflow through your engine (hence higher EGT's).

 

Go faster.. and the RPM's will be perfect with 315..

 

Dont worry about 1100-1200 egt's when towing those are ok, now if your holding 1450 for a long time then thats too hot. i will see 1400 sometimes but i back off after it hits that temp. the motor needs a little heat every once and awhile.

 

If you like the way your truck performs then don't worry about it. The 1100-1200 degrees is acceptable as long as your probe is pre-turbo. Won't hurt anything at those temps. A word of caution, keep an eye on the gauge when going into higher altitudes than where you live.

 

I'm stuck in that dilemma myself when towing my 12K trailer. If I drop down to 65 MPH with OD locked out, the RPMs are too high and my MPG is about 9.5 to 10. If I drive at 70 to 75 MPH in OD, the RPMs are good, but now the wind resistance knocks my MPG down to 9.5 to 10.

I could drive slower than 65 MPH, but that's pretty scary with the drivers we have in NV. I feel like I'm taking my life in my hands when I do that.

Tony

 

Drive 70-75 in OD You might get the same 9.5-10 but it takes you less time to get there. Thus you burn 9.5 - 10 for less time = saveings HAHAHAHA figger that out HAHA

 

Ya, EGT of 1100 or 1200 degrees is hot but I bet there are some aftermarket products out there that will help to lower those EGT's by 100 or 200 degrees, ie. intake, exhaust, etc.

 

EGT of 1100-1200 is normal there is noting to worry about.....................