I contacted Motul USA about suitability of Motul 5100 for G310R which has "diamond like carbon" DLC coating on the cam followers and wrist pin. He said that 5100 had almost no moly and was suitable for use in engines with DLC coating. It is important to stay away from oils which have significant amounts of molybdenum compound additives because the DLC coating can erode over time from interaction of the moly additive with the coating.
Motul 5100 also is suitable for machines with catalytic converters ( stay away from high zinc diesel type oils even though they may be JASO MA rated).
BMW recommends 15W-50 which seems a bit thick for a thermostatically controlled liquid cooled engine with internal oil cooler (inter-cooler which uses engine coolant to maintain oil temperature at the same temp as the engine coolant). On most machines, 10W40 would fill the bill for this setup with plain rod bearings and a 215 degree F thermostat, but I suspect that BMW recommends this relatively heavy weight oil because of the 6K mile oil change interval. In shared sump engines, transmission gears are responsible for shearing oil to a lower viscosity and the more miles you run, the more the oil shears. So theoretically the best, most shear stable 15W50 might shear to a 15W40 or even a 15W30 over 6K miles depending on how hard the machine was driven. It is good to start with a thick oil if you intend to stay with the recommended 6K OCI. In my humble opinion, I think 6K is stretching it, especially if you are running hard in warm climates. My preference would be to dump and replace the oil at 3K and replace the filter at every 6K.
