I run mostly on cheaper oils - semi-synh for cars, because it's quite slowly rotating engine, no need for expensive motorycle oils. Just replace the oil/filter at the time - every 10K kilometres and you're OK. I also replace gearbox and final drive oils at the same intervals - think how much work they have to do, and indeed, i know a rider who says the key to BMW final drive's long lasting is chaning it's transmission oils more often than manual suggests. I think the same goes to gearbox too, and it's quite cheap&easy to replace all the oils your own.
For engine in hotter conditions use SAE 20W-50 or 15W-50 oils.
[This message has been edited by Margus (edited 25 March 2005).]