Sawyer1

What is a safe all day towing EGT for a 2007 5.9 cummins and what about engine temp. Took a maiden short trip today and in OD tow haul mode with the Edge set on towing the engine temp ran at 203 F and EGT ran around 1000 - 1150 at 60mph. Would this be ok for say 6hrs at a time steady running or should I change to a lower thermostat for summer?

j_martin

Assuming EGT at exhaust manifold, it's made to run like that all day long. If that's after turbo, it's 100° or so too hot. Going down a gear usually brings it into line.

It would be good to back off long enough before a shutdown so it cools down a bit.

CoastalDav

Edge on Tow. Rig 15,100 lbs Truck 9040 full of fuel. 24,040 GCWR.

Towing on flat ground 780 to 850 if I remember right. 7% Grade 5 miles long
I-64 in West Va. 1115 to 1130 once you get it stabilized in 3rd gear at 45 MPH.

Running in OD on Cruise, it will climb to 1300 (Alarm on Juice) I down click on the cruise a couple miles per hour and run around 62 mph when towing to keep it under 1300. 6 % or more I'm in 3rd. Otherwise it don't downshift with the 4:10's. It did with the 3:73's. I use the Attitude monitor with one of the positions set for engine load. At 98%, if it stays there, I'll pull it down to 3rd. But usually it don't stay there when the boost picks up the load starts to drop fast.

Engine Temp is 200 to 205. 210 on the big hills.

If you have 3:73's you will run a little hotter due to the load.

Towing at 62 is 1900 rpm's. Runs better at 63mph approaching 2000 rpm.
The Magic number in 2150 rpm, that would be 4:30 gears at 62 mph.

Dave

Sawyer1

That's the problem,I have 3:73 gears so as soon as I hit OD then it is working too hard and if I shut off OD then I am reving really high to hold 60mph. What kind of mileage are you getting towing that king of weight? Are you towing with tow haul mode on in the trans or off and just using the edge tow setting?
Sorry for all the questions but I am used to a standard instead of auto trans.

CoastalDav

Towing my rig, which is most of the time being full timers, I get 11.5 on average, 12 sometime with a little stern wind, that's with a 57" wide Turbo Wing up as high as possible. Without the wing towing 10.8 to 11.2 at 62-63 mph. Without the wing on the truck with no trailer Edge on Mileage, 18.5 to 19. With the wing up not towing, 14-15 mpg. The wing is a big load. It also keeps the Front Cap on the Trailer clean almost to the top. Wind kinda hits
about 2ft below the top of the front cap. If I move the wing up any higher it will blind on coming traffic when I'm headed into the sun.

My mileage with the 3:73's was 20.3 non towing. 70 mph was 1900 RPS's.
70 now is 2100. I normally drive at 65 which is right on 2000 rpm's.

I have a triple lock torque converter installed and do not use Tow/Haul mode. The additional pressures seen in Tow/Haul really create hard shifts with the TLTC. I did not see that when I put it in or would have changed the
Valve body. Tranny now has right at 120,000 miles on it. So, if I keep the truck which I would like to do, replace the tranny with on of them good ones that will hold 1000ftlbs of torque and then push the juice up to Drive which
is advertised as 800 ftlbs on the rear wheels. Tow is advertised 730 ftlbs on the wheels. So flywheel torque has to be 850 and 800 respectively.

My previous truck was a 2000 Dodge with a NV5600 (204,000 miles) so me too. The exhaust brake was better with the 6sp than this auto. But performance wise the auto is much quicker.

I will be going to 4:30's if I get a heavier trailer.

Dave

KATOOM

The Cummins 5.9 will comfortably run up to a max EGT of 1250* for extended periods of time without issues. But that said, EGT's will affect engine temperatures as well so you have to monitor the the EGT's along with how hot the engine will run on long grades. Generally towing my 14-15k 5th wheel up long grades in the summer heat I can maintain hill climbs at about 1000* EGT and the engine will get no hotter than about 210*. Trying to push it any harder only creates excessive driveline heat.....as I have a temperature gauge monitoring everything under the truck.

Towing in OD is a heat generator and is very hard on the OD unit and the torque converter clutch. If you have a tranny temp gauge (which you should) then just make sure the tranny temp doesnt ever get above the 225* range and you're good. Whatever RPM's or gear selection it takes to maintain respectable EGT's, engine temp, and tranny temp, is what you'll need to run. The only way to lower all of those temps is to install better flowing intake and exhaust systems, and run better fluids with added coolers and fluid volume.

I have a manual tranny and I only tow in "direct" 1:1 ratio, which is 4th gear for me, and my RPM's at 60 mph are around 2200-2300. Thats not very high and dont overlook the fact that an engine towing a load needs to run close to its peak torque to run the most efficient.

Sawyer1

Thanks for all the responses. Gives me a bit of info to work with.

CoastalDav

Randy's Ring and Pinion on the web. Yukon Gears.

Best of luck, see ya on the big road.

Dave