Fair enough on the disbelief on the 200k oil story. I wouldn't believe everything some random guy on a message board told me, either!
If I can find a reference to it, I'll send it to you, just for pure acedemic interest in the matter.
I'm coming up on my first Boxster oil change. I'll let you know if it comes out black as it does in your Boxster, or yellow, as it did in my BMWs before this.
But yea -- it's funny how something like oil that has no bearing on any car except your own can cause such a debate!