I have passed this race quad down to my 13 year old daughter. She races it pretty hard, but doesn't rev it high like I did when I raced it. This KTM RFS engine has held up extremely well. It has a total of 122 hours on the crank and 48 hours since it's one and only new piston. I bought 3 cases of Elf 4Power 10w50 oil for a fair price to use in my race quads. Probably shouldn't have bought that much without really knowing what I was getting, but it turned out okay. This is my first sample with this oil and the first on this engine since the new piston. Oil looks good, sheared more than I would have thought (ELF 4Power is a PAO base stock oil), but you can see the wear metals are down, mostly to my daughter not running the engine as hard as I did probably. The engine has an oil cooler in place of the short oil filter.