i know of the diesel oils,anyone using or recommend a car 10w-40 that performs well in a wet clutch motorcycle engine? seen good deals on quakerstate,tropartic..some of the others are still fairly cheap...for now anyway.
Just about every sort of motorcycling group is using RTS these days, not just sportbikers. It's a very robust oil at a very economical price at American Wal-marts. It's a Grp. lll (if that concerns you) but considering that wet clutch applications likely beat down just about all oils in relatively short order, I see no advantage to going to a higher quality oil. I built up a decent supply of both RTS and Delvac 1 (super-cheap during a Wal-mart clearance!) so I shall be using that for a while. Once that is consumed, I am serioulsy considering getting bulk Delo 15W-40 from a local Peterbilt dealership. I can get it at $1.50 per litre. The forty-weight XD-3 works as well, though it would be more expensive at around $3.50 per litre at the Esso bulk dealer.
I do what John and Master ACiD do. I simply don't think synthetic with long OCI's is the smartest strategy in a wet-clutch bike application. And, if I'm going to change it pretty quickly anyway, I think a good HDEO does just fine. Cheap, too!