----- Original Message ----- From: "Bud Osbourne" <abcoz at hky.com> > Dean, > Everyone is entitled to his own opinion... Yep, and here is my opinion... Engines were running flat tappets long before ZDDP was around and they will be running flat tappets long after ZDDP disappears. My point is ZDDP is not the only anti-wear additive.