[sspade]

With BMW switching back to Castrol as their official oil supplier... I decided to look at all current EURO offerings.

Interested to hear recommendations on which oil they feel is "best" for our engines and (briefly) why?

Only one bears the official BMW approval, although one could assume that all of these would be sufficient. I personally change my oil every 5k like clockwork, regardless of one oils ability to last longer versus another. So that's a non issue. I have used both of the 40 weight offerings so far. Engine is N20 but this should also be relevant for the N55 considering the modular design/engineering.

Castrol EDGE Euro: 5W30 (c3)
Castrol EDGE Euro: 0W30
Castrol EDGE Euro: 5W30
Castrol EDGE Euro: 0W40
Castrol EDGE Euro: 5W40