06-19-2021, 10:20 AM
Don't use automotive oil, the additives may damage the coatings of the internal engine parts. In any auto parts store (Autozone, O'Reilly's, etc.) ask for Motorcycle Oil. They rarely have 5w-40, but I have found they always have 10w-40 four stroke motorcycle oil, with the BMW-specified API SL/JASO MA2 rating.