2011 R1200GS - only mineral oil allowed, ever?
Today, a BMW Master Mechanic told me that you can never use semi-synthetic or full synthetic oil in a Boxer engine, because, if you do, the engine will leak oil because the synthetic oils will damage the seals, and, you will also have oil consumption\burning problems.
I understand staying away from synthetic oils until the engine is broken in so that the rings will seat properly...but, to say that you can never use synthetic oils seemed strange...
Any insight or comments would be appreciated.
2011 BMW R1200GS