So many well-reasoned opinions. So many different conclusions.
What's a flat-tappeted guy to do?
I'm reminded of the five blind men who all thought they knew about elephants, but only really knew about an ear, a tusk, or a trunk. Who among us has trashed enough engines (and is certain what caused each one to die) to really know the big picture?
I don't really care too much which oil is best. I just need one that has been shown to work well in engines like mine. And since I know even less about oil than the blind men knew about elephants, I have to rely upon someone who does know.
Who better to ask than a long-suffering mechanic who has worked on hundreds of engines over the years? A guy who has had to pull apart 30 years worth of holed cases, busted crankshafts, and broken dreams? A guy who has had to figure out for paying customers, over and over, what worked and what didn't?
My mechanic says use the green stuff. And change it when it ain't green no more.
When it comes to stuff like this, I trust mechanics more than I trust engineers.
At least the blind men could all agree about how an elephant smells.