I'm like you and don't go thru a lot of bar oil now, but that's because I recently put in a gas insert, after almost 30 years of burning wood. When I did use a chainsaw a lot, I always used specific "bar oil" and not 30wt motor oil or ATF etc. My thoughts were that bar oil isn't all that expensive, and I used to buy it when it was on sale, and get several gallons. When I quit burning wood, I still had 3 or 4 gallons of Stihl bar oil left. Now that I don't use enough to make a big difference, I still use bar oil. It is supposed to have tachifiers (is that a word) in it, to keep it on the bar, and other things to break up gum and pitch. I dunno, but it just makes sense to me to use it. If for some reason I couldn't get it, I'd use the cheapest 30wt I could find. I'm not brand specific, I've used Stihl, TSC, SuperTech, and currently Echo, whatever is on sale, or convenient when I need some. For me a gallon will go a fair piece right now.