Boy I have read toooo many of these bar oil threads. On this site and on arobristsite.com.
General consenus is used oil is BAD. Sure, some get lucky and never have a problem. But those people are the ones only running a saw a few times a year and would only have to buy a gallon or two of bar oil anyway. So you are trying to save $15 or less
IMO the best bar oil I have found is the tsc stuff. It just seems to be tackier than the rest. And most of this year it has been on sale for 6.99/gal.
It is not the chain I am worried about. You can run used motor oil and still wear the chain out (sharpen enough there are no cutters left) before the oiling becomes an issue. But with bars costing $50 or so for a good 20-24" bar, replacing them more often than necessary is not something I want to do. Not to mention that used oil you are pumping through your oiler.Those arent cheap or easy to replace either. But to each is own.
If you are the guys running the $100 poulan walmart specials and running 87 octane gas, then use the used oil. But there is no way I am going to dump that in my $700-$800 saws. Not when bar oil is a minimal cost in a firewood cutting operation.
Would you put motor oil in your transmission, or hydraulic oil in your engine just to save a few $$??? Buy the right oil for the job. And if you are using MAXlife of whatever oil in your car and run that in your saw, that is bad news. Those high mileage oils have addatives that causes rubber seals and stuff to swell and seal again.(I think they advertise it as "renewing old seals). This is very bad on your rubber pickup hose.
And to the guy paying $38 for stihl oil, either you bought their environmentally friendly biodegradable vegtable oil, or they are seriously taking advantage of you. There regular bar oil is 10-15 bucks.