Just some info to take in;
I use mobile1 0w-40 and...
I had a 2000 323ci that I got rid of at 150k and that car ran like a dream
Then had an 01 330ci which also ran absolutely perfect, as if new. Got rid of it at 140k.
Now I have a 09 335i at 27k, bet your butt I'm using mobil1 0w-40. I only PRAY this car would run half as good as my old 3-series.