All you used oil haters can kiss my (well you know)
I have been using old motor oil for many years in the same saw with the same bar and still going strong. No issues what so ever.
You say it will wear a bar faster! Well a bar only cost 40 bucks on average. So say it does cause extra wear. Even at 6 bucks for the cheapest bar oil known to man. It is still cheaper to use old motor oil and replace a bar from time to time then spend all that money on bar oil.
As for the environment, cars drip oil on the roads all day every day, and mother nature kindly deposes of it.
Oil is a natural product of mother earth and she knows how to deal with it.
As for breathing it, your out doors and are more likely to breath the exhaust fumes then bar oil vapor.
So don't be hating on me for being smart enough not to spend good money on new bar oil when used motor has served me well for almost 20 years now.
Nobody is hating on you....I haven't seen a post lately telling you not to do it...
I've seen a post or 12 from you in every thread that even remotely mentions bar and chain oil saying the same thing you say every single post....we get it, you use motor oil. Nobody cares.