I've swapped out oil by myself since I bought my X in '08, and I use the Mobil1 stuff... never had a problem. (Other than the $80 bill at Advance Auto...)

I had similar pulsating upon braking, and in the end it was the tension struts and wishbones (on both sides) that I ended up replacing. And new brake pads. And new rotors. After I did all that, it fixed the problem.... A problem... one of....