4th UOA, 07 Yukon Denali w/6.2L, 10,200 miles, Mobil Delvac 1 ESP 5w30

Messages
215
Location
San Antonio,TX
Here are my latest used oil analysis reports. I do UOA because I find it interesting and educational. I hope you do too. I've been doing UOA on various vehicles and fluids(oil, atf, coolant) for 10+ yrs.

This time I sent a sample to both Blackstone Labs and Oil Analyzers Inc. Each sample was from the same load of oil out of my 07 6.2 Denali.

This was the first time that I've sent a sample for this vehicle to Blackstone Labs.

This is the fourth time I've sent a sample for this vehicle to OAI.
On the OAI report:
Oil samples 1 & 2 were about Mobil Delvac 1 ESP 5w40.
and samples 3 & 4 were about Mobil Delvac 1 ESP 5w30.

As you may recall? I had a plactic heater hose t-fitting break half way thru oil load #3. That is why the results were less than good. I replaced both t-fittings with the metal Gruven metal units. Lesson learned, if your engine gets hot, change the oil immediately. Don't run it for another 4k miles.

I believe the slightly elevated IRON in the latest results was from "rust" that may have been inside the steel 1 gal tank I added to my oil system at the start of this run.

My Yukon holds 11 qts of oil now. A yr ago, because of boredom from the CCP flu lockdown, I added an oil cooler, and a 1 gal steel external oil tank. The bypass filter system, with large 1 qt filter, has been in place since late 2018.

Here's some info on the oil, filters and vehicle:
Mobil Delvac 1 ESP 5w30 - 11 qts
Fram XG10575 full flow filter
Amsoil EaBP90 bypass filter
Vehicle total mileage - 167,440
Total hrs on vehicle since new - 5040
Total hrs on this oil - 222
Total miles on this oil - 10,240
Total time on oil - 1 year
Fuel used - 608 gals
Avg mpg - 16.8
Avg gal/hr - 2.738
Avg mph - 46
OLM - 13% remaining

6,000 of these miles was hwy driving at speed limits up to 80 mph in the western US on premium unleaded.
4,200 of these miles was local rural driving on a mix of regular unleaded and E85, or E20.
No towing.

I changed the oil to Costco Kirkland 5w30. I think I'll run premium unleaded only this time. We'll see how this oil holds up.

What say you?
Yukon OAI.JPG


Yukon BS.JPG
 
Messages
25,814
Location
Upstate NY
I would have expected the iron & silicon to be lower and TBN to be higher for a sump capacity that is almost double what came from the factory. I would check air intake.
 
Messages
16,963
Location
In the shop
All things considered I’d say it isn’t bad. Are you planning on cutting open the filter or did you leave it on?

Thank you for the UOA 🇺🇸🍺
 

jetman

Thread starter
Messages
215
Location
San Antonio,TX
Is it just me or does this look terrible, considering the lubricating mods?

I’d expect better results from just an average Denali and 10k on synthetic and a OEM filter.
Terrible? Can you explain? Both labs explained what they thought.

IMO, the results weren't bad, but I expected better from that oil. I only paid $10/gal for it. I guess I got what I paid for. I bought a lot of it and still haven't used it all up. I'm not gonna use it in the Denali anymore, its too hard on oil. I have a Toyota FJ Cruiser that's easy on oil and will use the rest of it up in that vehicle.

IMO, an OCI of no more than "1000 miles per qt of oil sump capacity" is a good rule of thumb for the L92 all aluminum 6.2 when a premium synthetic oil is used.
 

jetman

Thread starter
Messages
215
Location
San Antonio,TX
I like the 5w40 results and formulation better than the 5w30. Below are the specs. My OP here has the wear results.

There are differences in the two Mobil Delvac 1 ESP oils. Here's "virgin" results that I found:

5w30 & 5w40

Aluminum 8 2
Chromium 0 0
Iron 1 0
Copper 0 0
Lead 0 1
Tin 1 0
Molybdenum 0 50
Nickel 0 0
Manganese 0 0
Silver 0 0
Titanium 0 0
Potassium 0 1
Boron 78 134
Silicon 4 4
Sodium 3 9
Calcium 1170 1126
Magnesium 845 973
Phosphorus 756 1159
Zinc 819 1343
Barium 0 0
TBN = 11 10.2
 
Messages
592
Location
Minnesota
All I can say is that I would be disappointed with these results if I had put all that time and effort into "improving" my oil system.

Pretty difficult to classify the results as good or bad since the case is so unique considering the modifications.
 

jetman

Thread starter
Messages
215
Location
San Antonio,TX
Rural driving: doing short trips? Idling? Iron numbers are not looking good.
I am not a fan of diesel oils in gas engines.
Rural driving in my case means almost zero stop and go driving. Mostly hwy driving anytime I go somewhere. No traffic lights. When waiting in a drive thru line I shut the engine off.

The oils are not only diesel oils. Both are dual rated, spark and compression. Both meet or exceed requirements of API SN & SM.

5w30 specs

5w40 specs
 
Messages
12,349
Location
Colorado Springs
Rural driving in my case means almost zero stop and go driving. Mostly hwy driving anytime I go somewhere. No traffic lights. When waiting in a drive thru line I shut the engine off.

The oils are not only diesel oils. Both are dual rated, spark and compression. Both meet or exceed requirements of API SN & SM.


5w30 specs

5w40 specs
Yeah, I know they are duel rated, but primarily oil is made for vehicles equipped with after-treatment emission devices (DPF).
How long it takes for the oil to reach operating temperature? What is oil temperature with such a large sump?
 

jetman

Thread starter
Messages
215
Location
San Antonio,TX
My Yukon Denali has "after-treatment" devices. It has dual catalytic converters and four o2 sensors. All gasoline vehicles do nowadays. If oil residue gets on these devices bad things happen.

With this "all aluminum" engine, the oil serves a bigger role at carrying away heat than with a cast iron engine. It heats up fast(less mass). A 400 hp all aluminum engine in a awd 6000 lb vehicle = hard on oil.
 
Messages
12,349
Location
Colorado Springs
My Yukon Denali has "after-treatment" devices. It has dual catalytic converters and four o2 sensors. All gasoline vehicles do nowadays. If oil residue gets on these devices bad things happen.

With this "all aluminum" engine, the oil serves a bigger role at carrying away heat than with a cast iron engine. It heats up fast(less mass). A 400 hp all aluminum engine in a awd 6000 lb vehicle = hard on oil.
I am specifically talking DPF as after-treatment. That is the role of oils like ESP Delvac. An all-aluminum engine is nothing new. European manufacturers had that long before, and then some. If your oil takes a lot of time to reach operating temperature that could be the culprit behind elevated iron as that iron is not good, whatever engine it is. Just bcs. it has 400hp (and that is not some kind of achievement from 6.2ltr engine, so I would not call that overburden engine) and 6,000lbs it does not have to be hard on oil. I would think (and I could be wrong) that GM calculated what is a necessary sump to provide proper lubrication. If oil takes too long to reach operating temperature or stays below 212f, it is a problem.
 
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