Isn't bar oil made out of petroleum? If it is petoleum it is as harmful to the environment as used motor oil.
Ahhhhh...... no it's not.
Used motor oil is loaded with all sorts of heavy metals and chemical contaminants from combustion. You could drink a pint of clean motor oil and likely just get an upset stomach, spend a bit of time sitting on the toilet seat. A pint of used motor oil, if it didn't kill you outright, would put you in the emergency room with serious poisoning... and likely require a long, long time to full recover (if you ever did recover, some nervous system damage would surely be permanent). Used motor oil is classified as a cancer causing agent... but it's perfectly safe to take a bath in new, clean motor oil.
I wouldn't put used motor oil in a chainsaw (or any other machine)... after-all, I removed it from one machine because I felt it was harmful to leave it in there, why the hell would I pour it in another machine?? In my mind, using it in another machine makes absolutely no sense at all... but it makes a wonderful preservative for the wooden floors on hay racks and such.
Anyway, Stihl brand Bar and Chain Lube is good stuff, really good stuff, but there ain't any way I'd pay the price... it ain't
that much better than some less expensive Bar and Chain oils (but some of that "cheap" stuff is real crap also). I buy Chain Pro brand Bar & Chain Oil at the local fleet store... it's been a while since I bought any, but the last time it was on sale for $4.99 per gallon (normal price, $5.99)., and I have picked it up for as little as $3.99 during special "seasonal" sales. The bottle says it can be used in both winter and summer... which I do, without problems. It's really "tacky", the apparent viscosity changes little with temperature changes, it has never failed from heat (the gummy residue thing)... and my chains stay "wet" and clean during heavy cutting.