Google "mike miller's old school bmw maintenance schedule". Mike is the technical editor for BMW CCA and is one of the most knowledgeable guys on BMWs. He recommends stock or Redline oils.
E89 Z4 sDrive35i 7DCT "Zayna", Alpine White/Coral Red
E92 335i 6MT "Calixta", Space Grey/Coral Red [Retired]