^ I'm assuming you're talking about the bimmer. I've heard mixed reviews about Rotella. It is full of detergents and stuff that will eat up all the sludge, and crap that builds up in older engines. I would use it for one or two clean out cycles, and then switch to a quality synthetic. (Mobil 1) I'm sure Marshall could tell you all about Rotella, he swears by it. Keep in mind that sr knocked though... I have no idea if it had anything to do with running Rotella oil or not. My Dad always used BMW oil in his 5 series cars when they were newer and penzoil later in life.