Best motor oil for winter?

[gsotis]

Iam just about to do an oil change before winter hits on my 1994 530i. From what i read it sounds like 0w40 is the best choice, iam just not sure if that applies for extreamly cold winters (it gets to -40 where iam), is 0w30 better for this kind of cold. I also have 12 liters of 5w50 (it was on sale) laying around, how would this be in the winter and the summer. If anybody has any other oil recomondations please let me know. thanks.

[DueyT]

You could run 0W30 in the winter if you really wanted to (or lived in Minot, ND)...0W40 is fine, I run 0W40 year round on the cold North side of Lake Ontario...

Cheers,
Duey

[632 Regal]

0-40 is OK 0-30 is a good choice too, as long as its Mobil 1 synthetics. Dino oil would be like -15-0, dont recommend that.