Originally Posted by HighFive
I swapped to a conventional BMW branded 10w40, purely for matters of convenience, no other consideration (long story).
The oil leak stopped! Has not leaked again during the next 5,000 miles (including another oil change). Yes, I stayed with that same oil choice...because its not leaking.
I've seen it work that way many times on cars and trucks but have never figured out why. Even axle seals will often leak when you switch to synthetic. I always assumed it was more of a viscosity issue than anything else. Haven't had an issue on my bike so far. (Mine's happy with Redline 20/50)