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?
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