How long will Stabll stabilize gasoline?

From what I've read, gasoline should not be kept in a generator for long periods of time. It's actually recommended that it be emptied after each use. Stabilizer may help keep it longer, but it's up to you. Personally, I'd empty it to prevent any problems.

There is usually an expiration date printed on each stabil bottle.

Check the bottle of the Stabil and see what the expiration date is for this product, an alternate route is to call the manufacturers of both the Stabil and the generator. Then you have information on both products.

Fuel-stabilized gasoline keeps for one to three years.

Fuel stabilizers (like STA-BIL) are petroleum-based additives you can mix in with gasoline prior to storing it to slow oxidation and volatile compound evaporation and extend the shelf life of the gas. Depending on the product, the stabilizer can increase gasoline shelf life to between one and three years. Stabilizers work best when you mix them with new gasoline; they’re ineffective at slowing the degradation of old gas, and they can’t return contaminated gas to working order. I personally keep stabilized gas for one year.

We do a preventive run twice a year to make sure everything is in working order. Nothing like needing a small engine to run in an emergency and it won't crank. We use pure gas but have added Sta-Bil to ours as well in the past. I would recommend checking the date on the additive for a guideline but still crank periodically even if you don't run it completely out.

Although removing the gas is highly recommended, you can store the generator with the gas inside if you use a stabilizer to prevent corrosion. Gasoline will stay longer if stored in a cool, dry place and kept around 95% full with a commercial stabilizer added.

Old Fuel is Your Worst Enemy Stale fuel is the No. 1 cause of generator starting problems. If not, empty the tank and then run the generator until it's out of gas. Always use fresh, stabilized gas in your generator.

A good fuel stabilizer can double or triple the viable life of the generator fuel you're storing. Preppers will tell you that stored diesel fuel without any additives can be counted on for about 12 months. But that's only if the climate is temperate – around 70 degrees. The hotter it gets, the shorter the time limit.

here is info I found also if you look on your instruction manual it will tell you what to do and you can look online by your brand name of your generator to find the info online if you don't have your manual