Best use M/Cycle oil .15w40 says user manual. 5 litres for $30 bucks . Can use SF or SG grade car oil but check NO FRICTION MODIFIERS stated in formula. Any car oil rated SH SL SM SN etc WILL contain FM's and is therefore NO GOOD due to clutch slippage issues. Bike only needs 1 litre or so for a change. Oil filter coarse one in drain plug, fine paper or surg mesh one installed approx 2 oclock pos on RHS crank case, watch for 2 O rings on removing the 3 bolts/screws on small cover plate. If surgi mesh type just wash off with petrol and DRY then reinstall. If paper filter used then THROW AWAY. Don't try clean a paper filter.