What's the heaviest grade oil I can safely use on a newer Ford 5.4L 3v motor? Ford specs 5w20 for it (probably for CAFE purposes). I'm currently using PP 5w30. The reason I'm looking for a heavier oil is 2-part: first, I want the best protection I can get in So Cal's desert climates, and second I want to quiet cold-start clatter... As far as the cold-start noise, I saw a sizeable improvement going from MC 5w20 to PP 5w30, but it's still there sometimes.
Anyway, I live in the desert region of southern California. Summer sees temps in excess of 105*-110*. Winter probably averages 60*. So I don't think I have to worry about low temp oil flow that much.
Anyway, I live in the desert region of southern California. Summer sees temps in excess of 105*-110*. Winter probably averages 60*. So I don't think I have to worry about low temp oil flow that much.