I would stay away from the 5w50's and 0w50's, they have a lot of viscosity index improvers that will allow the oil to break down to a very thin 5w base stock. As I said before, I run the Mobil1 15w50 for this reason, it has no viscosity index improver and is easy to find in various stores. Being a synthetic allows you to run this viscosity in much lower temps than a conventional oil of the same weight, but if you need something for extreme cold I would recommend Mobil1 5w30 for due to it's lack of viscosity index improver and ease of locating in stores, as well.

Also stay away from the Castrol Syntec if you are wanting a true synthetic. Even the stuff labeled as a full synthetic is really just a highly refined mineral oil.

Redline, Mobil1, Amsoil, and Motul are all quality oils that come to mind....

 

http://www.exxon.mobil.com/maff/worl...motive/p17.htm

why would mobil one make motorcycle oil if automotive performed just as well? quote from posted url: 'Proven to enhance wet clutch performance...'

sure u could say that its just marketing, a way for them to make more money.... but i wont put any automotive oil on my wet clutch

 

One word, Marketing, it is done in every industry. They are not the people developing the product, they are the people told to sell the product with pretty packaging and flowery wording.

I pride myself on being an informed consumer and not paying more for essentially the same thing. Do you realize that many products are produced by one or two manufacturers and marketed by several 3rd party companies, all with their own claims and price points? Heck it even happens extensively in my profession, telecommunications. Some of the stuff I see would probably surprise you.

Once again, you are speculating on what automotive oil will do, I am speaking from years of direct experience. What direct impact has automotive oil had on your wet clutch, or have you just been reading what the marketing folks are feeding you?

 

I use mobil 1 10 30 in my 92 s10 121,000 and havent touched it yet. I also use mobil 1 15 50 in my atv, a 92 Warrior 435cc, pipe, cam,etc,,, I think mobil 1 came out with a motorcycle oil.