not exactly fuel:oil mix... however the answer is, somewhere around 100% oil
ran the boxer out of diesel a few weeks ago, used a VP premix can to get diesel because I didnt bring a can (mistake number one)
got the truck stuck and had to come back with another truck the next day, got diesel in a real can on the way, used said real can to fill the boxer up and forgot about the VP can
well, about 3 weeks later it bit me in the ass, filled my 194 up with diesel and didnt notice it till all the smoke on startup
reason 10000 I like to run my own stuff, NOBODY will pay attention to what fuel they are putting in a saw, listen to the skidsteer to make sure its running right, check the chip box isnt overflowing, or double check that they connected the trailer right
it is amazing how many times ive had to stop a job because people are stoopid!
p.s if you somehow run bar oil or diesel in a saw, simply pour the "fuel" out on a neighbors plants, re fill with mix gas and send it!