2021 GMC 3500 L5P Duramax - Rotella T6 5W40; Miles in Use 6,911; Oil Changed

[nutdriver]

This is the first UOA on this new engine. The oil is Rotella T6 5W40 with 6,911mi on Oil and 7,961 mil on Engine. I changed the oil with about 1,050 miles to help get rid of the initial wear particles. Mostly because I had a free sample sitting around, I added perhaps 3 ounces of Archoil AR9100 to the mix. The only surprise for me is the elevated potassium but as I recall that is most likely from my decision to add the Archoil additive. I did not add any make-up oil. I have not needed to add any antifreeze however the level has dropped perhaps 1 inch in the overflow chambers. I attributed that to purging some air trapped in the engine during use.

The new oil was a free change at my local GMC dealer. I do not plan to add any Archoil AR9100 to the new oil that went in. Any recommendations on what to do with the AR100? Is there any benefit to slowly using this product up in this engine?

The testing company was CAT SOS Laboratory. Their comments were just reporting normal break-in wear.


OIL Rotella T6 5W40
MILES IN USE 6,911
MILES on Engine 7,961

ALUMINUM 3
CHROMIUM 1
IRON 34
COPPER 216
LEAD 7
TIN 7
MOLYBDENUM 7
NICKEL 0
SILVER 1
POTASSIUM 200
BORON 271
SILICON 44
SODIUM 2
CALCIUM 2072
MAGNESIUM 202
PHOSPHORUS 1059
ZINC 1253

ST (Soot) 13
INSOLUBLES 0.4 Not reported
WATER N
OXI 20
SULFATION 24
NIT 9
V100 C 15.2

 

[wwillson]

What is the purpose of the Archoil?

 

[nutdriver]

wwillson - A couple years ago I was curious about Archoil's diesel fuel additive when I was driving a VW TDI to see if it would give me any mpg advantage. At the time, I was communting on mostly highway miles and small changes in my mpg were easily tracked. I did not see any mpg change and stopped using their fuel additive. As part of that trial, Archoil gave me a free sample of the AR9100. I am no authority but I believe that the AR9100 was mostly sold to improve striction problems in Ford PowerStroke engines. The manufacture is also claiming to decrease friction and decrease engine wear. I am not in anyway endorsing this product.

 

[mattd]

Is that supposed to be 1.3% soot? What unit is the “13”?

 

[wpod]

What is the purpose of the Archoil?

What is the purpose of a uoa on a new engine?

 

[nutdriver]

mattd - The units for soot are listed as particle count ct/ml. Looking at past results on other engines I do not think this is unusual. My last 2018 L5P Duramax report showed a soot count of 15 under similar conditions.

I found this past discussion involving this number. Certainly open to any other thoughts on how to best interpret this soot level.

Particle Count Discussion @ BITOG

 

[wwillson]

What is the purpose of a uoa on a new engine?

Is this a trick question?

 

[nutdriver]

wpod said:
What is the purpose of a uoa on a new engine?

wwillson​

Is this a trick question?

wpod - I guess I am confused as well by your question. To date you have 3,165 posts on BITOG and you do not see any value in a uoa on a new engine to identify a starting point?? For me it is partially curiosity but also to make sure that any problems that may be present in this new engine are identified before my warranty is up. I do not routinely do UOA on every oil change once I am confident in how the engine is doing. I also have benefited greatly from other uoa posts on this forum so consider this my contribution back to the group.