You don't want regular or synthetic car oil, it has anti-friction modifiers added to it. They will cause clutch slippage over time. Look in you owners manual or repair manual. It suggest Yamaha R4 or 10/30 API SE, SF, or SG. The stuff I found is SF, $1.88 a quart, Accel 10/40, on the shelf at Walmart, the shit works great, no clutch issues and plenty of lube for the gears. I'd definatley suggest buying better 2 stroke oil. You could get away with damn near anything in your crank case, but running that cheap shit in the fuel is just going to cause more carbon build up and provide much less protection for the crank and cylinder wall. Run some Klotz Techniplate @ 32:1 or 40:1. I run 40:1. Half a quart with 5 gallons of fuel. Its $10 a quart. It will smoke just a little on start up and when she warms up it will puff just a little when you rev it. Klotz is good shit. Amsoil and Motul is real good too.