07 Yukon Denali w/6.2L w/ 180+k mi; 6.3k miles on Amsoil ASM 0w-20

[jetman]

Vehicle is 2007 GMC Yukon Denali w/180,435 miles, w/all alu 6.2L L92. Mods are 1) 11 qt sump; 2) small hayden oil cooler; 3) 180*f thermostat; 4) 0w-20 wt engine oil.

Here's my latest used engine oil analysis report, It a OAI value kit (#KIT14)
Oil is Amsoil ASM 0w-20, full flow oil filter Fram XG10575, bypass oil filter is Amsoil EaBP90 installed 5 mths, 6235 miles, 126 hrs ago. DIC: 51% remaining. Averaging almost 50 mph on the oil 2/3rds hwy. This really the "6th uoa" report we've gotten since buying it almost 4 yrs and 40k miles ago. I sent the 5th to Blackstone labs. As you may recall? a plastic heater hose t-fitting broke Dec 2019 mths before report#3 which resulted in a short overheat event. I've been trying to get the IRON back down to these levels ever since. VOA Boron level is around 300.

This my first time to run 0w-?? oil in anything. I like what I'm seeing with this brand and wt of oil. Gas mileage locally (16.0mpg) and on the hwy (19.0) has increased noticeably. I'm getting 20-30 more miles per tank.

I plan to leave everything in place for at least 2k+ more miles unless someone has a good reason why I shouldn't?

What say you?

 

[Crusher]

Jetman
I think you stumbled into the right Oil for your Denali.
Your wear numbers look good, and you've got plenty of TBN left.
I like your incremental approach
Good Luck

 

[dnewton3]

The Fe wear rates are all over the place; Per 1k miles ... 5.0, 6.5, 19.5, 12.5, 6.5.
Not that things are "wrong", but there's a lot of inconsistency there that makes it hard to determine if things are OK or not.
No sensible correlation between the Fe and Si or oxidation or vis, so not really sure what's going on.

OK to procede, but do so with caution.

 

[jetman]

The Fe wear rates are all over the place; Per 1k miles ... 5.0, 6.5, 19.5, 12.5, 6.5.
Not that things are "wrong", but there's a lot of inconsistency there that makes it hard to determine if things are OK or not.
No sensible correlation between the Fe and Si or oxidation or vis, so not really sure what's going on.

OK to procede, but do so with caution.

I think u missed what I stated in post#1 here? "a plastic heater hose t-fitting broke Dec 2019 mths before report#3 which resulted in a short overheat event. I've been trying to get the IRON back down to these levels ever since".

 

[jetman]

Here are the results from Blackstone of the same sample (see post #1), Amsoil ASM 0w-20. The results from each lab are similar. These are the last 4 UOA reports since the "overheat event" (broken plastic heater hose fitting) in Dec of 2019. I hand wrote in the results from March 2020 (sample #3 in the OAI results post #1). I think its plane to see that the "overheat event" took a little toll on engine and oil. I should have changed the oil immediately. Vehicle has always run great and is only down 1/2 qt in these 6235 miles.
8-22 = Amsoil ASM 0w-20 - 6,235 miles
3-22 = Kirkland 5w-30 - 6,400 miles
3-21 = Mobil Delvac1 ESP 5w-30 - 10,200 miles
3-20 = Mobil Delvac 1 ESP 5w-40 - 8,600 miles

What say you?

 

[SteveG4]

Yes. The overheat event likely did take a toll. Though, it appears you've cleared that hump, and it's operating normally once again. The recent AMSoil OCI ran well for you given its low iron wear numbers, strong in-grade KV100 of 9.11 when tested, and its strong remaining TBN @ 6,200 miles. That oil could of or can run longer.

The Kirkland 5W-30 was also testing well @ 6,400 miles, though your engine's wear rate was still high at the time (probably still coming off that event). It would be interesting to try the Kirkland 5W-30 oil for the same mileage interval once again, seeing if the higher iron wear returns, or if it remains relatively low at 35 to 40. Last week's recent in-store pricing at Costco was either $37.99 or $38.99 for 10 quarts. Therefore, it's likely the value proposition -- if future iron levels remain low and you contain Kirkland OCI's to within 7,000 to 7,500 miles.

Keep maintaining her. IMHO, please run better than stock filters on that vehicle as well. Many of us like the wire or synthetic mesh backed media oil filters such as the Royal Purple, AMSoil, Purolator Boss, or Wix XP filters.

Also IMHO, for air filters, I've found the OEM heavy-duty AC-Delco or the Wix filters to be outstanding. I like these two in my Chevy truck: AC-Delco A3181C (HD) and the WIX 42488. These two should fit your vehicle. I've found them to perform in my glacial silt "dusty" environment.

Best of luck!