best 2 stroke oil that I know of is the penrite stuff,a tad expensive at $9 a litre but worth every cent,I'm 99% sure that it is mineral based but personally thats all I have ever used,always run in on a mineral oil,same with a car.In my Honda HR-196 mower I have always run gtx2 motor oil since new (600ml) and change it every 2-4 weeks depending on the amount of work done,goes in gold,comes out gold and I'm a contractor,im convinced that the bricks n crappin' oil sold for 4 stroke mowers is designed to blow your motor apart and offers no protection and S.F.ALL cleansing additives so clogs ur motor up etc
