For those that want to beat the stihl ultra and other jaso fd oils into a pulp try this. Take any crap chainsaw and ran the crap out of it with stihl ultra. Get it hot and run it like you want it to blow up. Then tear it down. You will find a slight oil film on the top and parts, and the bottom end will be nearly bone dry. Hardly any shine.
Do the same with echo red armor, vp racing, amsoil, or husky xp oil, and you will find a nice film on your top end, and a very slick layer on all of the bottom end maybe ever a small pool of oil in the bottom.
For me I have not done this on a chainsaw but have on echo gt 225, and a pb 8010 blower