My M54 has had a diet of 0w30 (I believe) each time it was serviced by BMW. However, castrol and many of the oil sellers out there say it should be 5w30, which I don't think is quite right. Also, people are going on about only using Castrol, which is what BMW would use, but its not ACEA A5 B5.
Would it be fine using THIS?
Would it be fine using THIS?