What about Royal Purple? That's what I'm running. But this is my "keeper" Mustang that I have no intensions on getting rid of I want to make sure I can get as much longevity out of it possible. Is my current oil good enough or are you saying Amsoil is that much better I should switch? My engine is stock for now but I run her kinda hard sometimes.
I can honestly say today, now that Royal Purple has reformulated their product, that yes....Amsoil has a definite edge.
Read ALL of this thread, post #10 is golden.
LINK