Although I don't agree that you should only run 'Stihl' brand oil ..... I do agree with the point you're trying to make. The brand name 'chainsaw mix oils' are NOT that expensive. So why even use outboard oil or something else? A 6 pack of 6.4 oz. bottles of Husqvarna mix oil is 23 bucks on Amazon. That'll mix 12 gallons of gas @ 40:1 .... or if you like living on the edge, mix it 50:1 for 15 gallons. For the average user or firewood scrounger, that's a LOT of chainsaw gas.