Regardless of the Dyno results on a limited number of one brand of sled, I think there is a strong case for using a manufacture recommended oil, or a high quality equivalent, I know some oil smokes more than others, which means it is putting out more carbon and particulates which has a negative effect on exhaust valves, and probably carbon buildup in the cylinders. Look at the new Cat oil for the 600 CTEC engine, It is a lot lighter than any other 2 cycle oils out there. I would think it would be very risky to run anything else, at least until the high quality manufacturers come out with a product that has the same specs and viscosity. I'm definitely not saying everyone should run the manufacturer labeled oils, but I do believe that oil makes a difference, and not all oils are created equal, even if they have the same certifications.