Rotella T6 in Cummins Dodge 2500

[A_Harman]

Truck Odometer: 199300 mi
Miles on oil: 12000
4 quarts of makeup oil added since last oil change.

From Polaris Labs.

Wear Metals:
Iron; 41 ppm
Chromium; 3
Al; 4
Copper; 4
Lead; 1

Contaminants:
Silicon; 8
Sodium; 11

Multi-source metals:
Moly; 66
Boron; 41

Additive metals:
Mag; 1162
Calcium; 1053
Phos; 1136
Zinc; 1377

Fuel Dilution Soot Water
KV100 = 14.2 cSt
TBN = 6.7
Oxidation = 12
Nitration = 8

Polaris Comments: Data indicates no abnormal findings. Resample at normal interval.

This is surprisingly good, considering that 6000 of the 12000 miles on the oil was towing. I expected much higher soot owing to the hard running. Maybe I'm not running it as hard as I have been thinking. And since I have been feeding the engine a steady diet of fuel blended with 10% waste oil, I expected the TBN to be much lower. TBN starts out at 10.6 for RT6, and it's only down to 6.7, which is only 45% used up.

KV100 tests right at the value that's on the TDS, so it's not been shearing.

It seems like I should be able to extend this OCI, but how much? Sample again in 6000 miles, and see how things look then?

 

[Ausfahrt]

Originally Posted By: A_Harman


This is surprisingly good, considering that 6000 of the 12000 miles on the oil was towing. I expected much higher soot owing to the hard running. Maybe I'm not running it as hard as I have been thinking. And since I have been feeding the engine a steady diet of fuel blended with 10% waste oil, I expected the TBN to be much lower. TBN starts out at 10.6 for RT6, and it's only down to 6.7, which is only 45% used up.



Nice report on a work truck. But just remember that the 4 quarts of makeup oil will raise your TBN.

 

[oggb]

Lookin good.

 

[dnewton3]

I would suggest you first establish some condemnation levels, so you'll know when to dump the load.

That said, there's plenty of life left in that sump load.

I would say run another 6k miles and sample, then make a decision. The only wear metal to watch at this point is Fe, and it's not terrible by any means. I would suggest a safe upper limit is 100ppm, so you're not even 1/2 way to the limit. Everything else looks fine and still worthy of service.

You really need to extend the OCI to get a decent ROI. But you'er on the right track.

 

[LouieLouie]

FWIW, I ran the old CI-4+ Rotella 5w-40 (Calcium was 3100!) for 9,900 miles with no make up oil and Fe had reached 104 ppm - this is in an '07 2500 with UOA from Blackstone and engine mileage at 23k.

 

[Gene K]

Condemnation Limits:
TBN - 1/3 Starting or 3.0 whichever is greater.
Iron - 200 PPM
Fuel - 2.5%
Silicon - 15 ppm over Virgin
Soot - 4.5%
Not sure how applicable these are to light duty engines.


If you have a non-EGR Engine or an ECM Program thats shuts off EGR then seldom is Soot an issue with ULSD and an engine in good condition. Its usually Iron or TBN.

Right off the top of my head Im guessing 24,000-30,000 miles based on what I see so far. But continue to test every 6000 miles.

 

[m37charlie]

Quote:
This is surprisingly good, considering that 6000 of the 12000 miles on the oil was towing. I expected much higher soot owing to the hard running. Maybe I'm not running it as hard as I have been thinking.


A 3/4 ton pickup, even towing some of the time, isn't "hard running" for Cummins. The exact same engine is used in the civilian version of the 5 ton FMTV 6X6 military truck.

Charlie

 

[A_Harman]

Thanks for the input on condemnation limits, guys. I'll sample again in 6000 and re-post.

 

[dnewton3]

Not to be argumentative, but I would counter that 200ppm of Fe might be a bit high. Most OEMs and lube makers tend to think around 100-150 ppm is more appropriate. Cummnins, in particular, limits at 75-100ppm.

Here is an article that has some research; check out page 11 of the study:
http://www.calrecycle.ca.gov/Publications/UsedOil/2008020.pdf

I've not ever seen 200ppm of Fe being an upper limit, but I would be willing to concede if good evidence indicated as such.

 

[Highline9]

Put a filter magnet on it. Maybe the iron will drop.

 

[Gene K]

Originally Posted By: dnewton3
Not to be argumentative, but I would counter that 200ppm of Fe might be a bit high. Most OEMs and lube makers tend to think around 100-150 ppm is more appropriate. Cummnins, in particular, limits at 75-100ppm.

Here is an article that has some research; check out page 11 of the study:
http://www.calrecycle.ca.gov/Publications/UsedOil/2008020.pdf

I've not ever seen 200ppm of Fe being an upper limit, but I would be willing to concede if good evidence indicated as such.


Most of my trucks are Detroit Series 60 and thats the condemnation limit they set when using PGOS 93K218 Certified Oils.

I consider those absolutes and am generally a bit more conservative with my own equipment. My personal "goals" are usually around 100 ppm FE, and 40% TBN (4.5 TBN) for instance. I say goals because those are what Im aiming for as an OCI as opposed to an absolute.

 

[Delmar]

Are you running a bypass filter ???

 

[A_Harman]

No, just a normal Purolator PurOne.