[clayfoushee]

Originally Posted by 4pipes

I'm thinking of switching from Kendall GT-1 20W50 to the new formulation of Mobil 1 15w50 that has higher levels of ZDDP.
http://www.mobil1.com/USA-English/Mo...t_Engines.aspx
http://www.mobil.com/USA-English/Lub...il1_15W-50.asp

Dave, I previously used Valvoline Racing 20w-50, and my oil pressures were 80 psi and above cold AND at RPMs above 3K warm, and only down to about 50 psi at warm idle. I switched to Rotella 15w-40, and they dropped about 10 psi on each end, which I felt more comfortable with, particularly at cold start-up.

Thanks Rick, it was your previous excellent research on solid flat tappets cams that motivated my change last year.