07 Yukon Denali w/6.2L w/ 173k mi; 6.4kmiles on Costco Kirkland 5w30

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Dec 15, 2010
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Here is my latest (5th) used oil analysis report since we purchased it 3+ yrs and 41k miles ago without mx records.

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 11+ yrs.

The vehicle is a stock 2007 Yukon Denali 6.2L all aluminum 400hp L92. I increased the sump capacity a couple of years ago to 11 qts. I also installed a small Hayden oil cooler. The bypass filter system, with Amsoil EaBP90 1 qt spin-on filter, has been in place since late 2018. Fuel used was Premium Unleaded. No towing.
Vehicle total mileage - 172,840
Total hrs on vehicle since new - 5215
Oil was Costco Kirkland 5w30. FF filter was Fram XG10575. Bypass filter was Amsoil EaBP90.
Total hrs on this oil - 175
Total miles on this oil - 6,400
Total time on oil - 1 year
Fuel used - 405 gals
Avg mpg - 15.7
Avg gal/hr - 2.33
Avg mph - 36
OLM - 33% remaining

This was the 2nd time that I've sent a sample for this vehicle to Blackstone Labs. Other times have been to Oil Analyzers Inc, or both.

The previous oil sample on this report was Mobil Delvac 1 ESP 5w30.

I'm not sure why I'm getting the slightly elevated IRON in the last 2 reports? I drive like an ole man. In the past most of our driving was hwy driving. This time it was used locally. Avg mpg and mph dropped from 16.8 at 46 mph to 15.7 at 36 mph. TBN was lower with 4k fewer miles too. It looks like shorter trips take a heavier toll on the oil which I believe is normal. And, maybe the Kirkland just doesn't hold up as well as Mobil Delvac 1 ESP.

I changed the oil to Amsoil Signature AZF 0w40. I got a 50% off deal on it because the dealer was moving to another state a didn't want to haul it. We'll see how this oil holds up. I installed another Fram XG10575 full flow filter. I drained and reinstalled the EaBP90 bypass filter.

What say you?
07 Yukon UOA BS 3-22.JPG
 
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The vehicle is a stock 2007 Yukon Denali 6.2L all aluminum 400hp L92. I increased the sump capacity a couple of years ago to 11 qts. I also installed a small Hayden oil cooler. The bypass filter system, with Amsoil EaBP90 1 qt spin-on filter, has been in place since late 2018.
To me, this is not a stock vehicle. Do you have an UOAs prior to the modifications? It would be helpful to know what affects the mods have on your UOAs.

I'm not sure why I'm getting the slightly elevated IRON in the last 2 reports?
That iron is more than slightly elevated. On average, it's more than 3x universal averages.

As BS suggested, I'd flush out the current oil early in case the iron is leftover from the modifications. Maybe even a couple of short oil changes before doing a full run with analysis.
 
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It's nice to see a UOA where the oil pushed to it's limlts. I keep seeing people running 15-20k oils and changing them out at 5K.
Because those 15-20k oils can only achieve that in absolutely perfect highway driving conditions, within >6 month period. No oil can survive SEVERE DUTY, stop n go & short trip city driving for 15-20k miles. 😆🤣
 
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I wonder if the huge oil capacity isn’t getting up to temp enough and although the engine may be hot, all that oil is not…. So the engine is running on cooler oil for longer vs a regular sump of 6qts. 🤷🏻‍♂️
 

jetman

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To me, this is not a stock vehicle. Do you have an UOAs prior to the modifications? It would be helpful to know what affects the mods have on your UOAs.
Here's the rest of the story (first 3 reports), before increasing the sump capacity, before installing oil cooler, before installing 180* thermostat: https://bobistheoilguy.com/forums/t...-2l-8600-mile-mobil-delvac-1-esp-5w30.324683/

Also, I ran an oil additive this last run: PolyDyn TX7. The only sign/effect I can see is that my wallet was $20 lighter ;)
 
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Because those 15-20k oils can only achieve that in absolutely perfect highway driving conditions, within >6 month period. No oil can survive SEVERE DUTY, stop n go & short trip city driving for 15-20k miles. 😆🤣
Re: "No oil can survive....".

More hyperbole, and just not true.

Folks need to remember that there is a highly profitable 'recurring revenue stream' that motor oil manufacturers need to protect, and using their marketeering morons to spread disinformation about extended oil change intervals is the main way they do it.

Modern synthetics have the advantage of NOT being paraffinic, and it is the paraffins that break down due to time, pressure and heat. Long-chain 'single molecule' synthetics are nearly indestructible. With very good filtration and appropriate filter change intervals, Delvac 1 ESP (for example) can 'survive' almost indefinitely. This is well documented. Note that the 3,000 hour oil drain interval used in this 10-yr test on a commercial marine diesel engine is roughly equivalent to 300,000 miles of typical automotive use.

Personally, I started running Mobil-1 in everything I own back in 1976 (in my 455ci 10.5:1 '70 Olds 442). I have never changed oil before 10,000 miles (frequently running 12k-15k), never had a single lubrication related engine issue and never sold a vehicle before 175,000 miles. Typically I change filters at least once before changing oil.
Currently I'm running Delvac 1 ESP with 500hr oil change intervals on a pair of Cummins 6BTA marine engines, changing filters every 100 hours. Same regime on a Yanmar 370 turbo diesel (commercial marine service), and Volvo (Vortec 8100) marine engine (gas). I've used similar regimes on twenty or so passenger vehicles over thr last 45 years; lately these are Infiniti G35 Xs, GMC Envoy 4.2L, Yukon Denali 6.2L, Mazda 929, etc, etc.

I save a LOT of money, time and mess by changing filters instead of oil.
 
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Here's the rest of the story (first 3 reports), before increasing the sump capacity, before installing oil cooler, before installing 180* thermostat: https://bobistheoilguy.com/forums/t...-2l-8600-mile-mobil-delvac-1-esp-5w30.324683/

Also, I ran an oil additive this last run: PolyDyn TX7. The only sign/effect I can see is that my wallet was $20 lighter ;)
Wow...VERY COOL. After the results you saw with Delvac 1 ESP, why switch (other than this seems like a fun hobby for you ;-) ?
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I would also suspect the iron levels are from the steel oil tank you added -- as you guess...
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Just curious, I saw a test where Amazon's brand of synthetic outperformed everything except Mobil-1 (and was very close at that). Have you thought about trying the Amazon synthetic? Also curious, have you thought about extending to 20K-30K miles on ESP (with filter changes at 'normal' intervals)? Commercial marine diesel operators are finding that 3,000 hours is no problem...

Thanks for all the great info!
 

jetman

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Wow...VERY COOL. After the results you saw with Delvac 1 ESP, why switch (other than this seems like a fun hobby for you ;-) ?
You like the Delvac 1 ESP, I don't. For the $8/gal it cost me, it was good stuff. But its all gone now.

It is a hobby for me. My Yukon and Toyota FJ are interesting experiments. The engines in my Toyota and Denali are relatively easy and inexpensive to replace if I destroy them. The FJ is easy on oil. The Yukon is hard on oil. Interesting :)

I didn't go with the Amsoil 0w40 in the Yukon at this last oil change, I went with 0w20 Amsoil. The results a yr from now will be interesting (to me).

I have a 1995 Detroit Diesel 12.7L 60 series in my Prevost motorhome that I don't experiment on. It would be difficult and expensive to replace.
 
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