Antonm,
Do not think you and I will ever agree on anything.
I disagree with you so often because you are wrong so often. You do repeat some correct information occasionally (likely without actually understanding why it's correct, I'm guessing the whole "blind squirrel" analogy fits here).
This one about the OLM, and changing the oil at 60% remaining, ranks right up there with your insistence that your particular 6.2 is special somehow and holds 9 quarts of oil vice the 8 quarts literally every other 6.2 holds
These newer DI engines that generate soot in the crankcase, dilute the oil with fuel, have DFM, Auto Stop/Start, Variable Cam Timing, roller lifters with needle bearing and the 10 speed transmission that loads the 6.2l up and lugs it down the highway is recipe for disaster.
Fuel dilution absolutely can be an issue in all engines , not just DI (ever take an oil sample on a carbureted big block? The amount of fuel in the oil is crazy).
But, do you wonder why our modern cars hold more oil now that they used to? Like the GM SUV's this board is about hold 8 quarts (well, except yours, which you think holds 9 quarts), and by comparison a 1970 big block Chevelle only holds 5 quarts? I'll give you a hint, its to allow for more capacity for holding contaminants before they become an issue which allows for a longer oil drain interval than 3K miles like we all grew up hearing.
Draining oil at 60% on the OLM monitor is the definition of pouring money down the drain. There is no actual benefit to throwing away good oil, only placebo effect.
We really need to go back to late 60's, early 70's maintenance in these newer vehicles. Sure the oil is better, but there are PLENTY of things working against the newer synthetic oils.
More mis-informed crazy talk right there. Fuel dilution was way worse back then because carburetors fuel dilute oil more than DI engine ever though about, and the oil capacity was lower.
In case the concept about oil capacity escapes you, lets say an engine has 4 ounces of fuel in the oil after a given amount of milage. In that 60's/ 70's car ,that holds 5 quarts, that would be 2.5% fuel dilution (which anything above 2% is considered bad).
Take that same 4 ounces of fuel and put in the normal 8 quarts of oil in one of these SUV's and its only 1.5% fuel dilution (so below where damage is likely to occur). In your special 1 of 1 engine that hold 9 quarts is only 1.3 %.
Also any oil you pick up off the Walmart shelf with a API SP sticker on it is VASTLY superior in every way to literally any oil you could buy in the 60s/70's.
Just the whole concept if "going back to the late 60's, early 70's maintenance" is ridiculous by itself. How long did those 60's and 70's cars last again? Plenty of modern cars go 200K plus, and unheard of feat for a 60's / 70's car without major component replacements (like multiple engine rebuilds).
There is no way I would go beyond 50% OLM in one of these newer vehicles, do not care how GM programmed the algorithm, they do not have the OLM programmed for engine longevity.
And you base this decision off what??? Your feelings?
Do some googling around, the GM OLM is not as evil as you think it is. For all the things GM has gotten way wrong over the decades, the OLM isn't one of them, it certainly isn't perfect (again its just an algorithm ) but it is pretty decent, and certainly not off by 60%.
Here's a video by a guy that's recently gained popularity in the motor oil scene. He's not saying anything that hasn't been known and written about for the last few decades, but I guess video has taken over from books as being the place people think reliable information comes from. While I don't agree with everything he says, you can a better picture of the GM OLM from him.
I am currently at 64% OLM on my current oil change, this equates to 2,722 miles at this point. I am guessing by the time I hit 60% I might be around the 3,500 mile mark, maybe a bit lower. The majority of my driving is highway. Typically when I start the engine it will run between 45 minutes to 6 hours.
The max I will run the oil in a modern vehicle is 4,000 miles. Oil analysis is not cheap, it is typically over 1/2 the price of what I can change my oil for, some of the more expensive provides the analysis is closer to 80% of what I can change my oil for.
I plan on keeping this vehicle for a long time as long as the 6.2l holds together. I would rather over maintain the vehicle than maintain it at GM's recommendations. So over 100,000 miles I might change my oil 2x more frequently that most people, but at the cost of the oil changes I could not even perform a single internal engine repair for the cost of the extra oil changes. Additionally if the engine actually holds together and I decide I want to keep the vehicle longer, you cannot turn back the clock on under maintaining the vehicle.
In hindsight I probably should have taken better care of my 2005 6.0l Yukon that has 275,000 miles on it at the moment, but it is what it is at this point. It is still a daily driver even though I have the 2024. The 2005 owes me nothing at this point and as long as there are no major expenses that come up, I will keep the 2005 running as long as I can, hell it may even outlast the 2024??
This last section of your post is just full of more mindless dribble. You can certainly do as you see fit (its still a free country for the moment), but just because that's what you choose to do doesn't mean its the best thing, or will result in the longest engine life.
Over-maintenance reduces equipment lifespan, obviously not an much as under-maintenance does, but over-maintenance still reduces lifespan because it introduces more opportunity for error and more opportunity for defective replacement parts to be introduced.
Do some googling and reading around about the bathtub curve of reliability. The cliff notes version is every time you open up , work on, or put a new part in that isn't needed in a piece of equipment you start back over at the left side of the curve. This concept is widely known, studied and practiced in the industrial reliability world where equipment downtime means money lost.
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