I have also been convinced somewhat, that taking the drain intervals to the max OLM and such are also contributing to the problem. While the oil may still technically be "good" by a lab report, that doesn't mean it actually still should be run. There is a build up of wear metals, contaminates, acids, etc that can have a detrimental effect on the AFM valves. While oil additives help mitigate the effects, things compound anyway. One of the reasons I decided to stay with no more than 5000 mile OCI's when I had my 1500 5.3L with AFM. I turned it off early on in the game, kept OCI's at 5000 miles, and I never used more than about 1/8 to 1/4 quart of oil over an oil change interval. Found out when I put on an oil catch can, where that oil it was using was going. Factoring out what the catch can captured over an oil change interval, my engine only was "using" maybe 1-2 oz of oil over that time. Pretty good.
For those already into the oil consumption game with their engine, I recommend a couple of times doing engine flushes with something like Amsoil Engine Flush. If one has the motivation, also removing plugs and doing a piston soak using AC Delco X66-P. That is some good stuff that can loosen up oil buildup on top rings. You have to do an immediate oil change. You put it in the cylinders and let it sit for several hours, then turn over engine (without plugs) to get the residual out and then change oil and reinstall plugs.
