Oil pressure is more function of bearing clearance, oil pump volume, and relief valve setting than the viscosity of the oil. As a general rule of thumb, heavier "low" number oils provide better cushioning between moving parts than water-thin ones, especially on bearings with a little wear and wider clearances.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!