hydro posted something a while ago that they reduced the amout of zddp in oil because it was screwing up cats. Ever since then I've been adding Valvoline Syn Power oil treatment in my Mobil 1 fills. The Redline fills get nothing additional.Originally Posted by vandy021
Bern, your boat always had top shelf Amsoil....if you like amsoil that is. I never cared for it.