I don't believe in all the theories either. I have a 2012 Hemi in a 2500 work truck. I get stuck in traffic quite a bit so it idles, I'm not turning it off every time I'm sitting. I change oil every 5000 miles. It's a work truck and I use it like one and don't have time to over think and watch my watch. At 243.000 miles I got a tick. I took it apart within about a week and found 1 lifter that the little roller bearings were gone and of course it started eating at the cam lobe. The other 15 lifters and cam lobes looked as good as new. Did that one lifter not get enough oil at idle, did that one lifter have dirtier oil on it? My belief is one lifter went bad. When putting back together I thought about leaving the windage tray out since that's what keeps the crankshaft out of the oil. Why don't they want it slinging oil every where especially the cam and lifters if that was the lifter problem? My theory is I had one defective lifter, if you can call anything defective after 243,000 miles. I replaced the cam, lifters, all gears, chain, guides and oil pump. It's been almost a year and still running as good as ever and just needing it to last until I retire in 2 years 7 months and 25 days, not that I'm counting!