I looked up the requirements for oil on my kids YZ85 and it has some JASO type grade requirements for the wet clutch. I looked up Rotella T and it has the JASO correct lube requirements. The only issue is the viscosity is 15w-40 instead of 10W-40 (would be a little thicker when cold, when warm it would have same viscosity-so I figured, no problem). I have just started using it in my RMZ as well as both kids YZ's. It is inexpensive for sure, plus I usually have a 5 gal pail around as I have a diesel truck.