Tis true on the Stabil shelf life. Think from bottle opening time it is 2 years. Always buy the smallest bottle you can find if you choose Stabil.I only use 100% gas in any of my lawn equipment, & I never drain them at season end either. I do add a dose of Seafoam to the 100% gas & run everything to get the mix well thru the systems.
Sta-bil has a shelf life to it, good to mark the date opened on the bottle after opening. It used to say as much on the bottle. maybe still does.
But it goes bad & gets sticky. That was my experience anyhow.
slomo