The best policy I found, short of using it for weed killer (all kinds of issues here) is to add it to good gas and burn it. Depending on how old the gas is (your nose will tell you as the older it is, the more it smells like turpentine) you should limit the dilution of your old gas to new gas to a maximum of 5%. This rule primarily applies to cars, you can go a bit higher when dealing with general power equipment. They are less sensitive to the old fuel (usually no fuel njectors or computers). I’ve regularly added 10% to power equipment items with no issues at all. Just use the fuel you’ve mixed quickly. Don’t let it sit around where it might continue the aging process.
What about gas from two strokes or gas mixed with oil? I have good luck mixing that fuel into a non-two stroke motor at 5%. I would not recommend doing this with any newer car.
Gas goes bad?
Yes, now with the new blends, it happens faster than ever. Gas that is left standing will go bad in as little as 3 months. The rule used to be up to 5 months, but that is changing with the new blends. This is one of the primary uses of the GasTapper product line. Old fuel leaves residue in fuel systems and burns with less energy than new fuel. We recommend cleansing your power equipment every 3 months with new fuel. The best way to do this is to either run the fuel out (not always possible) or pull it out and burn it in something that you are currently using. Replace that fuel with new fuel.
Should you use a product that extends the life of gas? Absolutely. There are several products on the market out there. We’ve had great luck with the Sta-bil product. This gives you a more comfortable window of 6 months or more depending on the temperature during storage. The warmer it is, the faster gas goes bad.