PRIG for gasoline will make gas last almost indefinitely as long as it’s not vented where you loose the light ends.
They advertise it can bring degraded (varnish smell) gas back to specs (barring it hasn’t lost all the light ends).
I can vouch for the latter. I had some bad gas and added the catalyst and the varnish smell disappeared. Ran the lawn mower just fine.
PRID for diesel
A good read on PRIG and PRID fuel stabilizers with an excellent comment near the end. https://rethinksurvival.com/review-of-pri-g-fuel-stabilizer-hands-down-the-best-available/
I will pass that on to mr. mm as that’s his department.
Thanks for the info.