i hit 2,xxx and changed to amsoil bought from our sponsor, a 50% mix 10-40 + 20-50 went for the first ride today and can say the vic much shifted better IMO. really do not know whats in their oil now, used to be group IV but not so sure looking at their MSDS, whatever is in it it works better than vic oil at NO xtra cost!!! i consider this a 15-45 "maybe" looking for a happy medium as pa does not usually get overly hot where a 20-50 is best IMO. most manufacturers recommend varying viscosities depending on climate, vics 20 as lo is not so good in colder weather + a 40 for very hot driving in traffic is not good enough IMO, but mine is parked below 50 usually! when your bike sets at 20-30 overnight and the afternoon hits 50 that 20 weight flows slowly into the needed areas of lubrication!!!