Its tempting to start using used motor oil. The last time I went into the local Stihl dealer he wanted almost $15/gallon for bar oil.
That's why I say its up to each person. A lot of folks are out of work,and will cut corners where ever they can. I usually buy bar oil on sale at TSC. But I would not hesitate to go back to Motor oil,if I had to. When I use it I mostly use new 30 weight and cut it in the winter with kerosene or 10 weight. When I use,used oil I put several layers of cheese cloth banded on a 5 gallon bucket and run it threw. Usually mixing it with new oil.
Like I said in a previous post I used motor oil both new and used for over 30 years. I never wore out one pump or a chain,I really can not remember the last time I bought a bar. The manufacturer wants you to use bar oil,and most will tell you theirs is the best. I would to if I could get a customer to fork out $10 to $15 dollars,a gallon.
I believe in doing what you want to do,I do not like being told I am stupid when something has worked for me for over 30 years. I will not call anyone stupid when things work for them. I am very libertarian in many of my beliefs. So I do basically what works for me,and have no problem if you do something different.
As far as clinging,if the oil isn't working the chain will seize. Years ago some off us tended to over lube with the hand pump and ran the oil tank MT before the Gas tank. You knew it pretty quick because you would lose pressure on the pump and it would soon heat up and slow down or seize. You just filled back up and poured a little oil on the bar and chain,and off you went. That link I posted about Veggie oil,said that no oil clings well when a saw is running over 13000 rpm's. I do not know if thats true.
Thanks Mark on that info on veggie oil. I may still filter some and try it my self just for fun. But now I know what to look for. One last thing I used Dad's saws until I got out of the service,in 1971. I bought my first saw that year. I still have it,it still runs and the pump is fine,and it has had gallons of motor oil ran through it.That saw is 39 years old,its probably older then most of you that are telling me I am going to ruin my saw.