To my knowledge, Castrol 0W-40 is not available...
in North America...the link was to the BMW NA Site, so that's probably why there is no mention of it there.
Mike, I'm assuming by your IP that you're in Canada...can you get Castrol 0W-40 there? I have not seen it here in the U.S.
As far as I know, Castrol 0W-30 (AKA German Castrol) is the only one they sell here that meets the BMW LL-01 Spec.
Vin
2003 530i (Sport Package) Build Date: 02/03
Titanium Gray over Black
Shadowline Trim
5-Speed Manual Transmission
Zeckhausen Modified CDV
Dinan Upgrades: High Flow Throttle Body, CAI, Stage 3 Software, and Free Flow Exhaust.
Horsepower: some is good, more is better, TOO MUCH is just right!
"If everything seems under control, you're just not going fast enough." ~ Mario Andretti
"What’s behind you doesn’t matter." ~ Enzo Ferrari