I got a catalogue in the mail from Amsoil oils. They have a 0w-30 weight synthetic oil that is suggested for vehicles that normally take 5w-20 or 5w-30 weight oils. Is this safe? It's expensive so it's gotta be good, right? I currently use Castrol Syntec. I was thinking about paying the money and trying amsoil out, but not if it causes wear by being too thin at startup.