Just saying this is what BMW calls for in the 2008RT owners manual
Engine oils of API classification SF or better.
Engine oils of ACEA classification A2 or better
That's what I use
Huh, interesting. A few years ago BMW was telling owners not to use any oil more recent that API SG. API SH, SL and beyond would void the warranty. Harley Davidson had a similar warning for their customers. BMW's name brand oil is API SG.
Experience is what you get when you don't get what you want.