Agree that you shouldn't get too wrapped up in which oil to use, any of the major brand API-SM oils, in a 5w-30, should do fine.

Personally I wouldn't switch to the Pennzoil Platinum, since it is labelled LL-04, which BMW have specifically recommended against using in the North American market (due to fuel quality, sulphur, ethanol). You can use it safely, but the caution is that it won't last as long, so you need to be changing it more frequently if you do decide to use it.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue