Lots and lots of opinions here. Most agree if you use full synthetic oils (and I think you should) then mix at 40 to one or perhaps a little more. If you use mineral oils (and I did this on 3 KDX) then mix at 32 to one. Lots of threads on mineral or synthetic oils. I do suggest that that for lots of reasons--tuning and others you choose a brand and type of oil and ratio and stay with it. I also try to use the same brand of gasoline, and for sure gasoline without alcohol! Cheers John