"Ed Pirrero"wrote
> Or, more likely, those boutique oils really aren't any better than the
> oils from the big companies, or they don't meet all the specifications.
>
> Shell Rotella synthetic at WalMart. Half the price of Mobil 1 (about)
> and meets all the Audi turbo specs.

Another reason could be that the Audi list which the OP was referring to was
only listing some (and not all) oils, mainly those that are easily
obtainable at most major auto parts stores rather than through mail order.

As for Amsoil, they claim that their 5w-40 European Car Formula surpasses VW
502.00, 505.00, 505.01 specs and many others. But then again, the wording
is such, that it doesn't clearly state whether it actually MEETS them.
Amsoil makes good oil, despite their sometimes questionable marketing
tactics, and I know this 5w-40 would do just fine in most VAG engines, but
if it's not on the Audi list and your warranty is at stake, you'd better
think twice.

http://www.amsoil.com/StoreFront/afl.aspx

Cheers,

Pete