Just got a 2015 Spyder F3-S SE6. Manual and owner's manual calls for 4 stroke XPS oil. I use Amsoil in my BMW bike. Looking on the Amsoil website it calls for, I think 10w-40 or 5W-40, can't remember right this second. Anyway, how important is it for this particular engine to stick with the xps oil? That stuff is to pricey and I get Amsoil through a friend at cost. What do you all run in the 1330 Rotax? I know that certain motors are finicky. Thanks