This is what convinced me. Quick, off to N.E.R.P.T. in 3....2....1.
https://motorcycleinfo.calsci.com/Oils1.html
I wrote a brief letter to Mark, the author of the above linked article. If you read the article, you know the man REALLY knows his stuff. Below is a copy of my email to him, and his reply. You might want to write some of this info down:
Mark
Several of us on the FJR forum have been checking out your "All about motor oil" article lately. One concern Ihave is that we don't know the age of the article, and the relevance of your findings... since we're worried that oil formulations have changed.One of our forum favorites was Shell Rotella 15w40 once upon a time, but Ihave heard they changed their formula for their
dino oil and that concerns me. I'm wondering how many oil companies have changed their formulations since your article waswritten.
Please advise.
Gary House > FJR forum
Everything has changed, of course. But the basic results haven't. Car oils are even worse for bikes now, and motorcycle or
diesel oils are still the best you can do. Diesel oils are getting worse, and perhaps in their next formulation I'll drop the
recommendation, but right now T6, Mobil-1 turbo diesel, Delvac-1, Chevron 5w-40diesel synthetic, and AMSOil remain your
best choices. Rotella, Delo-400 or Delvac 15w-40 are slightly behind but good choices.
Mark