Ryan'smilling
Addicted to ArboristSite
Just don't use liquid cooled oil in chainsaws.
Other than that, Im not too worried about what oil I use. I worry a bit more about an accurate mixture ratio.
I'd say that's good advice, but then you've got Scott Kunz (tree monkey) who's been porting and repairing saws for decades, and he swears by the Schaeffer's semi-synthetic 7000 series, which is a water cooled oil. He's put thousands of hours on some saws using it, and taken them apart also, with no negative results. Personally, I'd run that oil without a second thought. It's pretty cheap too compared to a lot of fancy oils. I think it's about $7/qt.