Well I guess my 30 + years of being a mechanic were all wasted. Unless you lived in the trenches a worked on thousands of vehicle's? All this thread is saying is how to prolong your engines life for as long as possible not leasing it or selling it in a few years and dumping it. Have you ever seen the “Car Nut” on YouTube? He explains it very well.
I appreciate your experience and recognize that high quality, clean oil is the lifeblood of any engine. That said there is no one size fits all approach...I think it is an "it depends."
For example, in the case of Honda, they
specifically do not want you changing oil early, because they like to have the assembly lube (whatever their secret sauce is) left in the engine for a full change interval. They call it out in the owners manual, and if you buy a new Honda and try to take it in to any Honda dealer and attempt to get your oil changed early, the dealer will strongly recommend (almost refuse) to do it. Have had this experience at 2-3 Honda dealers. Have owned 5 Honda's in my lifetime, 3 of which I still own, and the first 3 of them reliably went over 175k miles with nothing but the maintenance schedule...save one A/C compressor.
Certainly on these GM rigs, with some of their known complexities of the AFM/DFM and it's reliance on oil pressure in the galley for operating these features, any sludge, impurities, particles that block up the passeges would be a risk...I personally changed mine on my 6.2 at about 4500 miles (was just over 100 hours) on the first change, oil life was about 55% at the time. Did it because the dealer offered 2 free oil changes in addition to the first one included by GMC. But, the dealer ones had to be in the first 12 months of ownership...so, looked like I was going to hit 12k miles in a year, divided by 3, and got 3 of them free, each at about 4-4.5k miles.
Feels to me like if one really wanted to be proactive (some may say paranoid but hey, to each their own, right?), get about 20 hours on the engine (would think rings were seated by then), and then a change of oil and filter, and you would be seriously good to go to some longer interval.
My experience on my 2013 Suubrban w/ the 5.3 and AFM was that I did it by the oll life monitor, ran it to 15% life...until I got to about 85k miles, then my service manager advised going to a 4k mile interval...which I did. Traded that rig after 8.5 years and 120k miles, and it ran as well on the day I traded as the day I drove it off the lot.
2 (and a bonus) biggest things you can do for your ride to keep it going:
1) Check the oil at every fill up, and make sure it never gets low (even more important than changing oil)
2) Change the oil at the manufacturer recommended interval or before...
2a) Change the other fluids and filters (transmission, transfer case, rear diff, front diff, brake fluid) too...
