As a side-note to the examination of oil pressure-bearing clearances, several years ago I had an extended discussion with the people at Mecca about the subject. I was told, unequivocally, that creating more pressure by upping viscosity is actually guaranteeing poorer oil performance. Higher viscosity is actually, at a molecular level, created by having larger molecular sizes. Imagine tennis balls and B-Bs. The tennis balls would be much harder to squeeze through small spaces and the forcing would result in higher pressures. But B-Bs would do a much better job of filling the interstices and therefore a better job of supporting the surfaces involved and therefore making sure that the surfaces don't come in contact.
That sort of mental picture is what I summon up any time I find it necessary to envision what's going on in an oiling system.
KS
