How quickly should oil pressure come up?
I didn't think of that aspect of the oil weight. I ran 10w30 previously but tried the 10w40 for more idle oil pressure although it only gained me a couple of pounds. I also wondered about the filter drain back valve but I have had the "problem" with multiple filters. Maybe Wix filters aren't what they used to be like a lot of other brands. Honestly, I ran Fram on everything for years until people I assume know better told me they were no good. Never had any oil-related trouble.