I am installing a Rekluse z-Start Pro tonight in my '06 YZ450f. I called Rekluse to confirm whether or not they recommended a specific viscosity or type or brand of oil that works best with their autoclutch. The guy recommended the regular dino Rotella 15W40 (white bottle) that is made for diesel engines. I have been using the full synthetic 5W40 Rotella in my Aprilia street bikes for years with no trouble and trust the brand. My problem is with the non-synthetic. I have been using Castrol Syntec semi-synthetic 20W50 in my 426 for five years now w/ no problems either. My plan is to change the oil every 10 hours or so, which leads me to think that the interval is short enough that dino oil is fine. I like the price and availability of Rotella, but one siezed engine isn't worth it. I am not trying to rehash any of the Great Oil Debates. I am curious though if anyone is currently using the dino Rotella 15W40 and if so, what interval is your oil change? I know there are additives in diesel engine oil not found in gasoline engine oil, but what would the benefit be to my thumper engine if any?