I recently purchased a '94 530i and its time for an oil change. The
problem is that I have no idea what oil to use. I've looked through
the manual and it seems to recommend 15w-50. Now my car has a little
over 140k miles on it so I would like to use what's best. If it
matters, I live in Georgia so it gets fairly warm here in the summer.

Thanks for your help and sorry for such a novice question.