Hi all, I found this article while surfing on another motorcycle site.  It is lengthy, but reads quickly.  Not really sure it settles anything.  Interesting to note, my 2001 owners manual recommends SF or SG rated oil @ 10W-40.  These ratings are now considered old by most standards.  Ah, well, happy reading!   http://www.ibmwr.org/otech/oilreport.html