Originally Posted by 1bmw1
Can i ask why 10w60? Seems really thick.
Several reasons (for my S54 specifically)
-Higher revving motors = more heat. More heat = more expansion, hence looser tolerances for internal components like piston rings etc.. Thicker oil will not seep through those tolerances and burn during normal driving.
-Higher viscosity oils can with-stand high heat environments before breaking down
-Higher viscosity oils will not "walk" up the side of the pan during hard cornering forces, uncovering the pickup.
BMW recommends Mobil1 10W60 used on the S54 engine. From what I heard, if any other viscosity oil is used, the factory warranty could be voided. I'm sure they know what they're talking about. ///M stands for "much more money"... as in operating costs and maintenance.