Link up with Pablo or Gary, have them get you all the information regarding capacities, filters, etc., and then purchase Amsoil european 5w-40.
It will be the easiest move for you - everything will come from one place, and youll get a top-notch oil.
You can run delvac 1 5w-40, and Im not sure if many use it in the 9-5, but in other euro cars, rotella 5w-40 syn is popular. Delvac 1 is tough to find sometimes, even in its wal-mart iteration, a.k.a. turbo diesel truck 5w-40. Rotella is pretty easy to find.
Its your call. The site sponsors on here are experts and are top-notch.
JMH