What engine oil to use in servicing

[Grumpy Goat]

I've always used the BMW oil, mostly because I'm not sure how to determine whether other oils meet the requirements. The owner's manual states:
"... SAE 5W-40, API SL/JASO MA2, Additives (for instance, molybdenum-based substances) are prohibited, because they would attack the coatings on engine components".
So I get it that I need oil that is SAE 5W-40 which I understand, and API SL/JASO MA2 which I don't understand.

What I'm not sure of is whether anything in "API SL/JASO MA2" explicitly tells me that there are none of the prohibited additives. I have yet to see an oil bottle that says "...will not attack the special coatings that BMW Motorrad uses in their liquid cooled R1200 engines". :-)

API = American Petroleum Institute. Has standards against which oils are manufactured. See the oil categories here. Latest standard is "SN" but "SL" is fine.

JASO = Japanese Standard for special oils. Can be used in 4-stroke motorcycle engine with one oil system for engine, gearbox and wet clutch system. JASO MA means the oil is non-friction modified (as opposed to MB).

4T specifications
Modern passenger car engine oils contain more and more friction modifiers. While this is the good thing for those segments (reduces wear and fuel consumption) it's bad for the motorcycles. At least for those motorcycles which use engine oil to lubricate their transmission and wet clutch. JASO introduced the MA and MB specification to distinguish between non friction modified and friction modified engine oils. Most four-stroke motorcycles with wet clutches need a JASO MA oil.

The Liqui Moli doesn't seem significantly less expensive than the BMW Advantec. The price of the Castrol would make it an attractive alternative, if only I knew the answer to the above question.

If you use this Liqui Moly product in your RS you will be fine, since it adheres to the required standards.

Keep the molybdenum disulphide for your drive shaft splines. :D