2024 Chevy Tahoe LM2 Duramax 10,640 miles/212 hours on oil - 13,690 total miles/278 total hours - HPL 0w-20 Dexos D

wwillson

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This is the first sample of HPL 0w-20 Dexos D from my 2024 Chevy Tahoe with the 3.0L diesel. The engine did consume a total of 1 quart of oil during this 10,640 mile run. Approximately 9,500 miles was highway and the balance in town.

This engine will consume oil when operated at high EGTs. There is no magic EGT number when the engine starts consuming. However, the higher the EGTs the more it will consume. To me the oil consumption is not a surprise given that the 3.0L puts out 92 HP/L, which produces a ton of heat in the piston crowns. The oil consumption is likely from evaporative loss, which makes sense given the light base stocks required for a 0w. I have spoken to David at @High Performance Lubricants about the oil consumption and they will blend a 5w-20 or 5w-30 with base stocks that will minimize consumption as much as possible. Another example of HPL custom formulating and blending an engine oil for a specific application. How cool is that!

I still try to keep the EGTs below 1,100F by shifting into a lower gear, but sometimes that's not possible. Cruising 75MPH down the interstate uphill and into a headwind takes lots of power. Power makes heat and lots of it concentrated in those 3 liters of displacment.

Iron and silicon have increased, however the rate that Fe is being added to the oil is normal and silicon has increased but we don't know if it is still leaching from the sealants or if it is from ingested dirt. My guess is sealants. I inspected the air filter and found nothing physically wrong. The filter was visibly dirty, so I replaced it with an STP filter, which was the only brand AZ had on hand. We live in a dusty environment, so 15k air filter changes are probably going to be the norm. TBN and oxidation are stellar. I'm a bit surprised soot is 0.6%, but well below my condemnation point.

Oil filter is a PPE 114000650, which remains in service.

I have included the ppm/1k miles calculation, which makes the rate of wear and contamination easier to see.

Sample Information
Sample Date5/4/20245/5/20249/22/2024
Machine age miles3,0003,05013,690
Oil age miles3,0005010,640
Makeup oil quarts001
Filter age miles3,0005010,640
Oil changed?YesNoNo
Filter changed?YesNoNo
BrandOEMHPLHPL
Viscosity0w-200w-20 Dexos D0w-20 Dexos D
Wear Metals(ppm/1k miles)
Iron38(12.7)7(0)69(5.9)
Chromium<1<11
Nickel<1<1<1
Titanium<1<10
Silver6<15
Aluminum4311
Lead<1<10
Copper10293
Tin2<14
Vanandium<1<10
Cadmium<1<10
Additives
Boron4010670
Barium321
Molybdemum277174
Manganese2<12
Magnesium158761065
Calcium178111671387
Phosphorus879798769
Zinc927821907
Contaminants(ppm/1k miles)
Silicon104(35)23(0)44(2)
Potassium532
Fuel %<1<1<1
GlycolNEGNEGNEG
Soot%0.20.10.6
Fluid Condition
TBN7.912.5411.21
Viscosity8.28.99.1
Oxidation11.20(30)5.7(35.7)

edit - filter video added Jan 10, 2025

I finally got around to adding this video of the filter media from the filter used during this run of oil. The oil was changed on Oct 12, 2024 with 12,100 miles on the oil and filter and 15,000 miles total on the engine. The flakes in this filter are more machining chips being scavenged from the engine. Again, it's disappointing that GM doesn't do a better job of cleaning the machining debris from these engines.

https://bobistheoilguy.com/forums/t...iles-65-total-hours-hpl-0w-20-dexos-d.382762/

 
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Mighty impressive! The wear metals are ridiculously low in your engine.

I'm not a diesel guy, but I had no idea that 0W20 was now commonly recommended in modern engines. .

I'm curious.: what is your cruising RPM on the highway at altitude?
 
I'm not a diesel guy, but I had no idea that 0W20 was now commonly recommended in modern engines.
As far as I know, the 3.0L Duramax is the first GM diesel that recommends 0w-20

I'm curious.: what is your cruising RPM on the highway at altitude?
At 75MPH in 10th gear the RPMs are right at 1600, elevation makes no difference, except when I'm cruising in the flight levels, then I have to put it in 4WD to keep from spinning. :cool:
 
Iron and silicon have increased, however the rate that Fe is being added to the oil is normal and silicon has increased but we don't know if it is still leaching from the sealants or if it is from ingested dirt. My guess is sealants.
104 ppm Si on the factory fill in 3k miles suggests that quite a bit of silicon does leach into the oil when this engine's young. The 21 ppm increase in the last 10k miles is almost certainly mostly from sealant.

I wouldn't change the air filter every 15k miles unless it's very dirty. New filters have much lower efficiency. A restriction gauge might be a good investment. Another approach would be to weigh the new filter on a scale, then weigh it after 15k miles. Change it when you expect it will have picked up ~100 g of dirt.

Did you change the oil or just take a sample? It seems to have some life left in it, based on oxidation and viscosity, but given the engine break-in and the soot, I probably wouldn't go past 15k miles on this fill. Hopefully the ring seal will improve as the engine breaks in, and oil consumption and soot contamination will go down.
 
Yes, from 8.9 to 9.1, that's 2% which is negligible or even a lab error.
Even if it's not lab error, and if there's a bit of fuel dilution as well, some soot-thickening would be expected, so it's not necessarily oxidative thickening.
 
I don't have enough data to know what the stdev numbers are for this engine, but at face value the wear numbers are obviously break-in values and so it's too early to know what's "normal". I suspect things will settle down nicely as the miles accumulate. Of note, the Si seems to have gained a lot over 11k miles from its virgin value; I'll be curious to see if the air filter loading improves this value as it ages.
 
As far as I know, the 3.0L Duramax is the first GM diesel that recommends 0w-20


At 75MPH in 10th gear the RPMs are right at 1600, elevation makes no difference, except when I'm cruising in the flight levels, then I have to put it in 4WD to keep from spinning. :cool:

They used a 20 weight in the 1.6 diesel aswell
 
This is the first sample of HPL 0w-20 Dexos D from my 2024 Chevy Tahoe with the 3.0L diesel. The engine did consume a total of 1 quart of oil during this 10,640 mile run. Approximately 9,500 miles was highway and the balance in town.

This engine will consume oil when operated at high EGTs. There is no magic EGT number when the engine starts consuming. However, the higher the EGTs the more it will consume. To me the oil consumption is not a surprise given that the 3.0L puts out 92 HP/L, which produces a ton of heat in the piston crowns. The oil consumption is likely from evaporative loss, which makes sense given the light base stocks required for a 0w. I have spoken to David at @High Performance Lubricants about the oil consumption and they will blend a 5w-20 or 5w-30 with base stocks that will minimize consumption as much as possible. Another example of HPL custom formulating and blending an engine oil for a specific application. How cool is that!

I still try to keep the EGTs below 1,100F by shifting into a lower gear, but sometimes that's not possible. Cruising 75MPH down the interstate uphill and into a headwind takes lots of power. Power makes heat and lots of it concentrated in those 3 liters of displacment.

Iron and silicon have increased, however the rate that Fe is being added to the oil is normal and silicon has increased but we don't know if it is still leaching from the sealants or if it is from ingested dirt. My guess is sealants. I inspected the air filter and found nothing physically wrong. The filter was visibly dirty, so I replaced it with an STP filter, which was the only brand AZ had on hand. We live in a dusty environment, so 15k air filter changes are probably going to be the norm. TBN and oxidation are stellar. I'm a bit surprised soot is 0.6%, but well below my condemnation point.

I have included the ppm/1k miles calculation, which makes the rate of wear and contamination easier to see.

Sample Information
Sample Date5/4/20245/5/20249/22/2024
Machine age miles3,0003,05013,690
Oil age miles3,0005010,640
Makeup oil quarts001
Filter age miles3,0005010,640
Oil changed?YesNoNo
Filter changed?YesNoNo
BrandOEMHPLHPL
Viscosity0w-200w-20 Dexos D0w-20 Dexos D
Wear Metals(ppm/1k miles)
Iron38(12.7)7(0)69(5.9)
Chromium<1<11
Nickel<1<1<1
Titanium<1<10
Silver6<15
Aluminum4311
Lead<1<10
Copper10293
Tin2<14
Vanandium<1<10
Cadmium<1<10
Additives
Boron4010670
Barium321
Molybdemum277174
Manganese2<12
Magnesium158761065
Calcium178111671387
Phosphorus879798769
Zinc927821907
Contaminants(ppm/1k miles)
Silicon104(35)23(0)44(2)
Potassium532
Fuel %<1<1<1
GlycolNEGNEGNEG
Soot%0.20.10.6
Fluid Condition
TBN7.912.5411.21
Viscosity8.28.99.1
Oxidation11.20(30)5.7(35.7)

I believe the EGT limit in my 2.0 jtdm was 1500°F before power got reduced. But I ran at least 0W30A3/B4 in it (with MB229.5 approval) so limited evaporation losses. Ran very good on Red Line 20W-50 though. that engine made 102 bhp/L.

One thing you can look at is intake charge temps. A drop in intake charge temps equals a drop in EGT aswell, so if you see a possibility to reduce those by 50F during hard use, that might just keep you below 1100F aswell.
 
I wouldn't change the air filter every 15k miles unless it's very dirty.
I have learned with this and other vehicles I own that the air here in the front range is very dusty. The load in the filter after 15k miles was quite surprising to me
.
Did you change the oil or just take a sample?
Just sampled. I will run this oil to around 1% soot, which will be reached long before TBN or oxidation would condemn the oil.
 
One thing you can look at is intake charge temps. A drop in intake charge temps equals a drop in EGT aswell, so if you see a possibility to reduce those by 50F during hard use, that might just keep you below 1100F aswell.
The 3.0L Duramax has an air to water aftercooler. The coolant circuit is self contained, meaning the charge air circuit has its own coolant reservoir, pump, piping, and radiator. The average charge air inlet runs about 250F, while the outlet runs about 100F or about 15-20F above ambient temperature. It's a very efficient system.
 
what filter was in use for this interval?
The much larger than stock PPE. Thanks for the reminder, I added an oil filter comment to the OP.

 
Over these 3 UOA the contaminates have come way down in very short time. IMO it was due for change though since Si was still elevated like you stated. 1 qt over 10k miles of 0w-20 in a diesel engine doesn't seem too bad but I think it's a wise investment to try running a xw-30 to see what happens. It may reduce oil consumption as it breaks-in more & things settle out w/more miles put on.

A 15,000 mile ODI would put soot at 0.84%
A 18,000 mile ODI would put soot at 1.01%
A 20,000 mile ODI would put soot at 1.12%

I'd sample the oil at 10k miles to see what it shows for Si & others. Extend from there if you can. Wear & contaminates are still improving so it's somewhat hard to gauge right now & that is the beauty of future UOA as you well know. :cool:

As it stands right now 15,000 mile ODI would put you at 97 ppm Fe but that is probably off & could go further once you confirm via UOA at 10k. Enjoy that Tahoe & it is very nice of HPL to do what they are doing.
 
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I would not be using a 0w20 if I had an LM2 or LZ0. I've seen posts on forums about unacceptable valvetrain wear and UOAs with 5w30 that had significantly lower iron PPM. The problems reported with oil consumption could also be reduced or mitigated with a thicker oil.

I'd be using Amsoil ADN 10w30 or RLI Biosyn HD SAE 30 (10w30) in it and changing it every 10K miles.
 
I'd be using Amsoil ADN 10w30 or RLI Biosyn HD SAE 30 (10w30) in it and changing it every 10K miles.
10w-30 doesn't have the cold cranking required for my geography. I'm going to use HPL 5w-30 that they custom blended to have low volatility. HPL is my choice because they have established a reputation here of awesomeness.
 
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