How Old Does Gasoline Get?

[Hippo393]

How long does unleaded gasoline stay OK in the gas tank whilst the 4Runner is getting fixed?

The 1997 4Runner V6 in question blew a head gasket in March of 2023. Had her towed back to the house that day, and am still putting her back together.
At the time of the incident, we had and still have a 1/3rd full gas tank. Yes I put Sta-Bil in it over the last (almost) 2 years. Is that gas still good, even if I dilute it with good gas? I will be ready to start her up in a month or two...and if old gas is bad, then I will be glad to drain & replace it. But if there are ways to make what's in there work when I start her up, then that could be better if it could be done safely.

Getting close to resurrecting this truck...do I drain/siphon the old gasoline, or other strategy?
Thoughts? Several searches on this topic for me were not successful.

Thanks gang!
-Alan
Huntersville, NC

 

[pluton]

Siphoning it out (is it possible?...don't know) leaving only enough to get to the gas station would be my choice. I store 2 20L metal gas cans full, and have used that gas up to about 1.25 years after filling and it's been fine. But that's in a sealed can with very little air space in it.

 

[Pyral]

Being safe I'd say a year, extra safe 6 months. I've used ethanol gas that was years old in landscaping equipment but I wouldn't put it through my car.

 

[jgue467]

in my experience with atvs at deer lease 2 yrs with alcohol fuel treatment is the Absolute limit - ask me how I know.

Now after repeated lessons at seasons end - I drain what is left in tank and run engines till they die until next season.

In your case I would drain the gas and get a 5 gallon can to get some Fresh stuff into it unless you want to risk nasty turpentine issues - btw how does it Smell - you will absolutely know when it is beginning to turn - nasty odor.

 

[2TH4IST]

As others have said, drain the tank and put fresh stuff in. Gas made now isn't what it used to be.

 

[hugho]

How long does unleaded gasoline stay OK in the gas tank whilst the 4Runner is getting fixed?

The 1997 4Runner V6 in question blew a head gasket in March of 2023. Had her towed back to the house that day, and am still putting her back together.
At the time of the incident, we had and still have a 1/3rd full gas tank. Yes I put Sta-Bil in it over the last (almost) 2 years. Is that gas still good, even if I dilute it with good gas? I will be ready to start her up in a month or two...and if old gas is bad, then I will be glad to drain & replace it. But if there are ways to make what's in there work when I start her up, then that could be better if it could be done safely.

Getting close to resurrecting this truck...do I drain/siphon the old gasoline, or other strategy?
Thoughts? Several searches on this topic for me were not successful.

Thanks gang!
-Alan
Huntersville, NC

I avoid ethanol gas period in all my many cars and 2 cycle engines.It gathers water and probably lasts 6 months or less. I think Stabil works marginally for ethanol free fuel but is probably useless for ethanol fuel. The web is full of reviews for better products. I used to use old fuel to start fires burning brush. That's all its good for.

 

[alumarine]

As jgue467 said, how does it smell?
If it smells like gas, then it's probably good.

 

[phattyduck]

I'd probably just drive it straight to the closest gas station and fill the rest of the tank with 91 octane.

Keep in mind that you might have fuel pump or fuel injector issues with long breaks between running the engine like that. Suspect fuel injector(s) if you have misfire issues in the near future.

-Charlie