2021 Chevy Duramax L5P - 21,900 miles/503 hours on oil - 43,400 total miles/997 total hours - HPL 5w-40

[wwillson]

This oil sample has a total of 21,900 miles and 503 hours on the oil. I had intended to pull a sample at 20,000 miles, but the truck needed to do real work, so the oil change had to wait. Almost all miles since the last UOA have been pulling tall and heavy. The average fuel consumption is right at 9 MPG, so the engine is working hard. I try to manage the EGTs, but there are times when you have to take what you get. The oil consumption in the last 6,450 miles is 1 quart for a total of 2.75 quarts consumed in the last 21,900 miles. The total make-up oil with oil filter changes is 3 quarts.

This analysis shows the Fe rate at 6.0ppm/1k miles. The trend is higher in the last UOA, but virtually all of the 6,450 miles is pulling. The viscosity has increased from 14.4 to 15.2 which is acceptable. The corrected oxidation is 7, which is far below Wearcheck's condemnation value of 25. The soot is 0.8%, which is also acceptable. Cu decreased and Si didn't increase, could these be lab errors? TBN is still 13.38 I'd say that's still serviceable I will change the filter and cut it to see what was caught.

Would you change this oil? If so, why?

Previous UOA:

2021 Chevy Duramax L5P - 15,450 miles/387 hours on oil - 37,000 total miles/882 total hours - HPL 5w-40

This is my 2021 Chevy 3500 DRW L5P Duramax that pulls a 20,000 pound 5th wheel for a combined GVW of 29,500 pounds. I'm still pulling in eighth gear and oil consumption continues to be very low, but not zero. There have been two oil filter changes so far in the OCI, which combined required about...

bobistheoilguy.com

Sample Information						Oil Changed
Sample Date	6/23/2021	07/17/2021	8/24/2021	4/4/2022	7/1/2022	8/10/2022	1/18/2023	4/17/2023	8/16/2023
Machine Age miles	2,500	2,700	8,900	16,000	21,500	21,550	31,300	37,000	43,400
Oil Age miles	2,500	200	6,400	13,500	19,000	50	9,750	15,450	21,900
Machine Time hours	55	62	214	350	495	496	734	882	997
Oil Time hours	55	7	152	295	440	1	239	387	503
Filter Age miles	2,500	200	6,400	7,100	4,000	50	5,000	9,800	8,400
Oil Changed	Yes	No	No	No	Yes	No	No	No
Filter Changed	Yes	No	Yes	Yes	Yes	No	Yes	Yes	Yes
Make-up oil	0	0	0	1.5 qts	2.5(+1)	0	1	2(+1)	3(+1)
Brand	Factory	HPL	HPL	HPL	HPL	HPL	HPL	HPL	HPL
Viscosity	15w-40	5w-40 CK-4	5w-40 CK-4	5w-40 CK-4	5w-40 CK-4	5w-40 CK-4	5w-40 CK-4	5w-40 CK-4	5w-40 CK-4
Wear Metals
Iron	12	4	36	67	102	16	61	85	132
Chromium	<1	<1	2	3	4	<1	2	2	4
Nickel	<1	0	0	<1	0	<1	<1	<1	1
Titanium	<1	<1	<1	<1	<1	0	<1	0	0
Silver	3	<1	<1	<1	<1	<1	<1	<1	0
Aluminum	<1	0	15	13	14	3	8	9	13
Lead	6	1	2	4	3	1	2	0	2
Copper	109	28	85	188	203	29	185	197	158
Tin	6	1	0	6	6	2	2	2	2
Vanandium	<1	0	0	<1	<1	<1	<1	0	<1
Additives
Boron	120	15	12	21	6	3	14	17	0
Barium	<1	0	0	0	0	0	4	0	4
Molybdenum	2	514	450	504	537	541	469	574	603
Manganese	<1	<1	<1	1	2	<1	2	2	2
Magnesium	672	995	968	1008	924	913	831	1001	936
Calcium	1260	2439	2414	2557	2459	2375	2111	2722	2606
Phosphorus	1000	1099	1029	1064	981	973	847	968	916
Zinc	1155	1179	1148	1285	1233	1159	1078	1292	1256
Contaminants
Silicon	87	33	48	46	54	18	21	27	27
Sodium	7	5	3	3	5	2	5	8	10
Potassium	11	2	43	55	59	6	16	21	30
Fuel %	<1	<1.0	<1.0	<1.0	<1.0	<1.0	<1.0	<1.0	<1.0
Glycol	NEG	NEG	NEG	NEG	NEG	NEG	NEG	NEG	NEG
Soot%	0.1	0.1	0.4	0.6	0.8	0.2	0.6	0.7	0.8
Fluid Condition
TBN	8.55	14.9	13.3	13.7	10.8	13.9	13.76	12.86	13.38
Viscosity	13.9	14.5	13.8	14.97	14.5	14.4	14.5	14.5	15.2
Oxidation (normalized)						0(40.6)	2.5(43.1)	3.5(44.1)	7(47.6)

 

[dnewton3]

Fe wear rates are not changing much at all; typical variation +/- 1ppm is very acceptable.
Cu wear rate dropped; not sure why but that can't be a bad thing.
STRONG base level still active; nothing wrong there.
All this while towing heavy loads for sustained duration. Outstanding!

Keep on trucking!

 

[RDY4WAR]

I second what dnewton3 said. Good report considering the use. That TBN retention is phenominal.

 

[wwillson]

@dnewton3 @RDY4WAR you didn't say if you would keep running this oil.

 

[RDY4WAR]

He said to keep on trucking, and I second that.

 

[dnewton3]

Keep on trucking = extend that OCI.

 

[fantastic]

You just aren't playing around! Getting your money's worth would be an understatement.

Here's my 2c...

You can probably ignore the TBN since it appears it will not be the downfall of this oil & would probably be something else that ends it. Sodium trended up & then came back down then ticked up slightly. Is it burning it up, is it being deposited in some crack, watered down from adding oil? who knows but it's trended down overall & is now at a decent level.

Boron is 0 & I think it's an additive that gets depleted but you've been adding oil so not sure why it shows 0.

Iron IMO keep it under 200 PPM I personally wouldn't run anything that far but that is your call. Al is low. Viscosity doing well. It may be the iron load, Copper Load, or Silicon that limits this oil but I don't think its quite there yet. I do think the Copper is high but I don't know enough to make a judgment on that. I concur with the other great leads of this board... Motor on my friend. 50k sounds like a great milestone & you are almost there.

 

[MSCH]

at a certain point I imagine the cost of sampling outweighs the cost of a cheaper brand of oil and just changing it more frequently. But since it sounds like you are happy with the experiment side of this, I think you ought to leave the oil in there and see how far out you can go before you give up and just change the oil.

 

[DirectRejection]

Extend !
Vampire sample at 25k miles would be interesting.

 

[DirectRejection]

wwillson, the "template" you mentioned and use here is most useful !

 

[wwillson]

wwillson, the "template" you mentioned and use here is most useful !

It makes the UOA chronological progression easy to visually follow.

The neat thing about the table is that Xenforo understands how to convert a pasted spreadsheet into a table. I keep a spreadsheet and just copy and paste into my post.

 

[cptbarkey]

On the chart soot seems to be consistently rising at the same rate every 10k on the oil. Black stone says less than 2 percent is ok. What level would be a cause for concern? If it stays at the same rate of increase 40k seems ok?

 

[wareze]

When you retain TBN, does that mean that you also retain the oil additives?

 

[wwillson]

On the chart soot seems to be consistently rising at the same rate every 10k on the oil. Black stone says less than 2 percent is ok. What level would be a cause for concern? If it stays at the same rate of increase 40k seems ok?

This is an interesting question that has no clear answer, even from GM. You'll see soot condemnation levels as high as 4.5% in some over the road trucks. I have stated before that soot loading > 1% is probably going to be my limit. However, @dnewton3 has data from the Duramax engines that show little or no correlation between soot loading and wear. Maybe he will chime in on the topic of soot and provide some data.

 

[wwillson]

When you retain TBN, does that mean that you also retain the oil additives?

A high TBN means that the alkalinity hasn't been depleted.

 

[Dodgetracker]

WWillson is this oil off the HPL shelf or did they blend it for you?

 

[cptbarkey]

This is an interesting question that has no clear answer, even from GM. You'll see soot condemnation levels as high as 4.5% in some over the road trucks. I have stated before that soot loading > 1% is probably going to be my limit. However, @dnewton3 has data from the Duramax engines that show little or no correlation between soot loading and wear. Maybe he will chime in on the topic of soot and provide some data.

Ran across this older post where he talked about bypass filtration and soot is very very small. His data showed a steady increase to 2%, a further increase 2-4%, but then parabolic increase past 5%. Very informative. thank you for answering and appreciate the knowledge.

Do you run a bypass filter system? Why?

If you do, what made u decide to do so? What results have u seen?

bobistheoilguy.com

 

[wwillson]

WWillson is this oil off the HPL shelf or did they blend it for you?

This is off the shelf 5w-40 CK-4

 

[Pokoki79]

This is off the shelf 5w-40 CK-4

Heavy Duty, Premium Cold Climate or Premium Heavy Duty?

 

[wwillson]

This is the Heavy Duty, the entry level for HPL HDEOs.