It all depends on the ambient temperature. In cold weather, 10W50 or !0W40 is better. In hot climate, 15W... is better. I am always surprised, how people indiscriminately follow manufacturer's 'recommendations' like a holy bible without considering all the variables. In my Versus 1000 manual, at least Kawasaki says - 10W40 or 15W40/50 depending on the country. higher viscosity oil gives more protection, but is problematic with cold start, etc... The modern engines commonly call for lower viscosity, but at the end, one will be ok with any oil as long as it is good quality... The reason BMW insists on the particular oil is because they make money by selling it... I use Mobil1 10/40 in gs, as I ride it in high mountains during winter season.
as you love riding, you need to love you bike
Last edited by Kris; 05-25-2019 at 02:18 PM.