I like the PENNSOIL 2 stroke semi synthetic myself, I think they now call it the XLF formula. The super tech oil is fine for premixing, and many here and elsewhere have run it with good results. I avoid the MERCURY oil like the plague as the stuff smokes like crazy, and also made my prop hub slimy and oily black. YAMALUBE is another good oil, but high up on the price tag. I will say that PENNSOIL is good stuff. My old 140 sat out on a stand for at least 4 years without starting, yet it still had an fil inside the cylinder walls when I tore the heads off to put new head gaskets on it. That to me right there says something if the oil still had residue left after over 4 years. It has been independantly tested for air cooled use, and found to outperform many air cooled rated oils. And air cooled oils are meant to be used in engines that run a good 40-60 degrees hotter, so oil breakdown is a huge concern.