Hi, thankyou all for your advice/input, I had a read of manual and it said,,preferred bmw longlife 01, so I searched online bmw LL 01 and to my surprise most off the listings were Mobil 1, I was expecting to see castrol as that is what is printed on my oil filler cap, so after much deliberation I narrowed it down to Mobil 1 5/30 or castrol edge 5/30 as 5pterson has suggested, is 5/30 the preferred ratio. ��