[masraum]

Mobil 1 has a good rep, although I've heard that it's not what it once was.

Here's some info from a synthetic oil thread

What exactly constitutes synthetic oil is a debatable subject... I personally stopped using M1 years ago when they abandoned using 100% polyalphaolefin (they now use mostly Group 3 ultra refined dino oil with a little polyalphaolefin thrown in). If 100% polyalphaolefin is what you want, I think only Redline, Amsoil, and Motul still sell it these days.