I also favor the Rotella T6, but recently Had a real good conversation with a rider friend that has worked in auto parts and oil lubricants for many years. His opinion is all about the "Zinc" being removed from the hwy oils through a Federal EPA or some Regulation. This Federal Regulation did not include Off Road Vehicles, Motorcycles, and a few other categories that I am not completely sure of and could include Rotella because of the diesel use, but being honest, don't really know.
The Motorcycle and ATV Oils still have the needed "Zinc" in them. That is why I have been using Oils like the Honda, Yamaha, and Kawasaki Blends that have been readily available to me and others.
NOW, having said that, it isn't meant to undermine anyone here on the forum, rather just offer more information that could help in some way. I'm thinking I will stick with the Major Motorcycle "Blends" and get as close to the 5-40 as I can get for my SC Region and average temperatures I operate my Spyder in...MD in SC
"Never choose Luck when Knowledge is the best option"
2009 CanAm RS SM5 Spyder
Red & Black