Yeah...I don't get it either. 1/50th of what you are burning is bio-based (well...technically, oil is bio-based too, right? - but you know what I mean!). The rest is gasoline. Plus it is getting burned up...once it is carbon and smoke, I don't think it matters if it came from a plant that was alive this year or a long time ago.Stihl oil, silver bottles, notes it Biodegradable.
That's a big turn off for me. I don't feel a oil should be Biodegradable or have a shelf life.
It would make me wonder if that gas is still safe if it sits for anytime.
I can't even figure out why they would do such a thing since I don't think they have many Environmental people in the chainsaw industry.
It does make some sense for bar oil. That isn't getting burned up, but flung all over the yard/woods. I've been using straight Canola for about 5+ years now. Probably not a big deal, but Canola works great and is just a touch cheaper too, so that is what I use.