The GM TSB (not "memo") was because of the location of the oil pressure sensor and the possible surge of oil volume at a cold start-up that could happen (and cause the oil filter to bypass crud with thick cold oil, even with 0W-20) before the variable pump output volume could become controlled. I think you're misunderstanding the big picture on that one. Doesn't mean the engine needs more oil flow because the engine is "starved" or needs/has more oil flow because it uses 0W-20 oil. A regular old PD pump could do a fine job too, but at the cost of maybe a hair of lost fuel economy but with less complexity.
You have flow specs of the old pump vs new pump designs vs engine RPM to verify there was a big increase in flow with the new pump? And comparitive oil temperatures between the engines also showing more flow was needed when using 0W-20?
Yes, I have a single point of view/focus, and your claim that I've "mis-spoken" about why variable oil pumps exist is false. Every write-up about them says what I've said why they exist, so you might as well just call me a liar because that's how it came across when I read that comment, even though every article written (including SAE articles) say the main reason VVOPs exist is to save fuel. That's the focus, and the variable volume oil pump wasn't invented for any other reasons, regardless of how you might think it pertains to your specific engine. The bottom line is they are to help save a miniscule amount of fuel. Good that they work, but like I said more complicated than they're worth IMO, and could care less if anyone agrees or not.
Probably best at this point since you can't show any proof that VVOPs weren't invented to save fuel and instead for some other reasons. Agree to disagree as it's just going in circles now.
