I have a new Xtreme 125cc stock motor with aftermarket cooler and I wanted to see what people prefer for oil. I know this is a big debate and I'm trying not to get everyone stirred up. I've only used 20W50 Valvoline 4 stroke oil and the clutch is slipping already in 3rd and 4th (changed it 3 times already withing a week) . I generally use Rotella 15W40 on my 400EX and don't have any clutch slippage at all even with it being bored out and a Hotcams installed. I like the Rotella because you can get a gallon for $11 at Wally-world and sometimes less at the parts stores. I'm thinking of running that in the 125 but I've never tried it in anything other than my 400EX. Opinions on what is good as well as inexpensive?