http://forums.roadfly.com/forums/bmw...=956159&page=1
So depending upon how you read this, XJ and/or syn oil is right for all BMW diffs, so unless I read otherwise officially from BMW, 140 it is back there... If out of warranty and gas goes up to $4-5, a 110 may provide reasonably similar protection in all but extreme transient use, while providing 1% efficiency improvement.