crainholio

Amen. New EPA-mandated oil formulations are prioritized on catalytic converter protection, reducing zinc/phosphorous quantities.

Cats are easier to replace than valvetrain components, so I stick with SL spec oils like Mobil-1 High Mileage or Valvoline VR-1.

93Polo

Some test results some of you may find interesting:

http://www.chevelles.com/forums/show...674&highlight=
http://www.chevelles.com/forums/show...762&highlight=
http://www.chevelles.com/forums/show...921&highlight=

vettenuts

Interesting, will be a long read but thanks for the link. Maybe I need to switch some oils around that I am using.

racebum

if you use royal purple that test data is a great excuse not to, that on top of the fact their freakin additive pack doesn't address the seal shrinkage problem of a PAO base stock

one thing i never noticed in any of that was cycling or wear over time, it was all film strength when not, not when 300deg or not after 4k miles

one reason i'm a big time redline fan is based on how well that oil holds up to hours on end of constant high rpm use and heat