A convert from the Magnum V10 to the 6.7 TD

[MichaelBorum]

Just bought my 2012 long bed srw last month. So far, so good. But a couple questions from a diesel newbie:
1. Why is the oil so black? I assume it was recently changed because I'm not getting any notifications.
2. Is it really okay to run in Tow/Haul mode with the Exhaust brake active all the time?? I read about folks claiming that soot buildup is minimized by doing so.
3. What's a typical temperature for the transmission when max towing? I live at high altitude and will be hauling a truck camper and towing a jeep on a car hauler. At what temp do I get worried?
4. Along those lines, there's no monitoring of exhaust gas temp, but my friends with other TDs claim I should be adding gauges to check. Isn't this already compensated for by the Ram engineers by design?

/Lilfoot/

 

[RustyJC]

1. Diesels produce particulate emissions (soot - partially oxidized fuel). Diesel oils are formulated to carry this soot in suspension as opposed to letting it plate out in the engine as deposits; therefore, the oil quickly turns black with suspended soot particles.

2. Yes, you can run in tow/haul with the exhaust brake active. Tow/haul modifies the shifting schedule and raises transmission line pressure for firmer, later shifts. The exhaust brake consists of the movable nozzle ring in the variable geometry turbo moving to its minimum nozzle area position when you release the accelerator pedal. This creates exhaust back-pressure which the engine pumps against during the exhaust stroke, thereby creating negative (retarding) horsepower which slows the truck. The movement of the nozzle ring prevents carbon buildup. This practice also prolongs the life of your service brakes.

3. Towing our 5th wheel, I'll see 160 to 170 degF at constant speed on the Interstate. The excessive heat is generated in the lower gears with the torque converter unlocked and minimal ram air flowing through the cooling pack. I've seen spikes to 215 to 220 degF towing the 5th wheel up low-speed mountain roads with switchback turns that don't allow the truck to get out of 1st and 2nd gear as well as during sustained periods of exhaust braking on steep hills in the lower gears.

4. The computer algorithms won't let a stock truck get into trouble on EGT - remember, FCA has to warranty these things for 100K miles!! Once you begin to modify the truck to override these algorithms, then you need to monitor EGT.

I also towed 5th wheels years ago with a 1996 Ram 3500 V-10/47RE. The diesels are quite a change, aren't they?

Rusty

 

[MichaelBorum]

Thanks for the quick, knowledgeable, and very thoughtful response. And, yes, driving this truck just makes me smile! I took a 200 mile trip towing my Jeep on a 18ft trailer, and I noticed several places that my '99 V10 would just bog down, especially when starting a long climb at 8000 ft. altitude from a complete stop. This one just acted like it had at least 50% more to give, and I never felt the need to press hard down on the accelerator (almost said "gas" pedal). I am so looking forward to dropping the camper on it and going!

 

[RustyJC]

Naturally aspirated engines such as your V-10 lose 3% of their sea level horsepower for every 1000 ft increase in altitude. Therefore, at 8000 ft elevation, your V-10 only had 76% of its sea level horsepower available. The Cummins turbocharged diesel, however, holds its sea level power rating up to 10000 ft elevation. The turbocharger speed simply increases roughly 3%/1000 ft to compensate for decreasing air density, so the engine doesn't see any change in mass flow until the turbocharger reaches its speed limit, so it holds sea level horsepower.

Rusty