What Bob Cowan said [good post], and what i was saying earlier in the thread. Thinnest
oil to maintain the pressure. and there is a prominent engine builder in the West who said that 40W will stabilize the hydraulics lifter at high rpms.
better then 30w. My guess is that tolerances can vary on the hydraulic plunger in the lifter. (like bearing clearances, arrrrghh)
Lake Speed from [Gibbs Driven] and I had a discussion about
oil viscosity. I was looking for 10-40 in Hot Rod
oil and they don't make it. He said as long as its from the same stock, I could mix the 10w-30 and 15w-50 Hot Rod oil and in effect end up with 12.5w-40. Interesting huh. Told you it can get complicated.
I don't know anything about Porches but alot of guys use 40 to 50w oil for some reason.
The discussion is about our style engines, and that's where my information and experience comes from, 60w is alot of viscosity, and if that is what is needed to maintain oil pressure at an idle or revs then I say it's built loose, or it's leaking from a restrictor.