My 2009 Silverado Crew Cab Z71 4x4 (5.3L LC9 V8 flex fuel, 3.42 gears, 6-speed auto trans) was progressively getting thirstier over the last year and a half or so, up to the point of where it was drinking around 4 quarts of 5W-30 over 5K miles. Regular dino-oil or synthetic, and Fram's best or AC Delco PF48 oil filters seemed to make no difference whatsoever. Seemed to always use more oil during hot weather, on long trips where AFM was kicked in longer. I do not haul heavy loads or tow anything, nor do I race it--don't remember ever flooring the throttle on this truck. I do most of my own maintenance work and am picky about meeting or beating the factory service intervals and using quality oils, etc., and now use only PF48 oil filters.
I was getting fed up with this oil usage situation, and worried that using that much oil was going to mess up my catalytic convertor, etc. Local service manager says "yeah, a lot of them AFM motors do that!" which didn't help my situation any or make me feel any more comfortable about my purchase of any present or future GM products.
The last few months I started reading more on the internet about AFM engines using oil and what to do about it. So I started driving in Manual mode on the transmission around town (5th gear selected) so AFM would not kick in. Thought I could tell the oil usage was slowing down. Then I purchased and installed the Range V8 module to turn AFM completely off. After a couple of months and a few thousand miles, my oil usage has all but stopped! I'm hoping that the oil usage will stop completely, but at this point, I could live with a quart being used over a DIC OLM-indicated oil life interval if I have to, as it would certainly be a relief not to be pouring in a new quart in less than a thousand miles like I used to have to do. (Can't believe I just said that, as up to now I always viewed any oil usage in a non-abused motor as being unacceptable. But when life gives you lemons. . . )
So this was not a scientific study by any means and I anticipate being bashed by the AFM-couldn't-possibly-cause-any-problems crowd. But the fact is that NOTHING changed with my oil, filters, gasoline, driving habits, etc. over the last few months with the exception of TURNING OFF AFM and then my oil usage has ALL BUT STOPPED. I am not a paid spokesperson for Range or Blackbear or any vendor or anybody else, but am personally convinced that turning off AFM stopped my oil usage and would recommend others with oil usage problems to look into turning their AFM function off as soon as possible. My miles-per-gallon has not dropped noticably, either, since turning AFM off, so I'm not sure how much it really helps save gas, anyway.
Cheers, and I hope this helps somebody.