I'll second the premature wear on the engine...My step-father ran regular 5w-30 in my current 300D, the car made it about 3miles, and spun the #2 rod bearing. When I finally tore down the engine a few years ago, the connecting rod journal was stretched out so far that I had to cut the rod in half with a torch to get the piston out!!

Tell me there isn't much pressure on those bearings!!!

well went to AutoZone and they took back the oil!!!!!!!! So I looked and the only thing they had was Rotella T 15W40, I heard it's good, should it protect my Engine, it has CH-4 and other ratings?