How long will a 5 gallon plastic containers of fuel stay fresh?

  • Related: mechanics.stackexchange.com/questions/119/…
    – Jason C
    Commented Sep 24, 2016 at 5:54
  • I have a Ford Mustang that has sat for two years only ran it to go get the smog check now it's coming up on 4 years I started it and drove it a few miles last week and it ran just fine how often almost 4 years old
    – Jorge
    Commented Mar 27, 2018 at 22:25

5 Answers 5


The API (American Petroleum Institute http://www.api.org/) recommends that gas is not stored for more than two years in an approved container without fuel stabilizer. There are stories on the internet (so they must be true!) of people using gas up to three years old without problems.

I can't verify that, but I have used gas over a year old in my 4-stroke lawnmower. Mix the old gas with some fresh gas (the more the better) and voila: now you have double the amount of crappy gas, and it works just fine.

  • I spent a lot of time searching around on the API site and was unable to find any guidelines for storage length, only safety. There is a Quora post that says that API basically says to definitely get rid of it after 2 years, but independently of whether or not it goes bad before that. That's what Quora says, at least, but the API page it linked to no longer exists and the archived version of it doesn't actually mention the length of time; so I'm not sure the Quora citation was accurate to begin with.
    – Jason C
    Commented Sep 24, 2016 at 6:08

About 3- 5 months in a sealed container, or 6 - 8 months with fuel stabilizer added. Recommended maximum storage is 1 year.


  • 1
    Do you have any citations for that information? Commented Sep 23, 2016 at 9:52
  • It may stay "fresh" (will not sour) with stabil but octane loss cannot be prevented after about 6 months storage.
    – Moab
    Commented Sep 25, 2016 at 0:21

Here's yet another set of numbers. According to Exxon (emphasis mine):

In general, gasoline should be used within a month of purchase. When the engine will not be used for an extended period of time, it’s best to drain the fuel tank and then run the engine until it stalls. If you choose to store gasoline and follow proper storage guidelines, the gasoline can be expected to remain of good quality for at least six months.

Where "proper storage guidelines", according to that page, are, paraphrasing:

  • In an approved container.
  • Tightly sealed.
  • At room temperature.

If you add a stabilizer, usually in the product description it says how long they're good for. Most seem to claim about a year.

After a modest research effort this is the only source I was able to find that verifiably came directly from a party involved in the gasoline industry.

Anecdotally, in my experience I don't generally have problems running generators off of gasoline stored for 3-4 months (I do this often), but I have had to flush / replace fuel lines on generators that have sat for a year or longer with fuel in them without being run.


I just used high octane premium gas to run a two stroke snow blower and a 4 stroke machine. The gas was in the red plastic gas cans and approximately 3 years old. I wasn't going to use it, but it snowed 18 inches and it was all I had on hand. It worked just fine. I don't recommend, but didn't have any troubles and iI will use the rest up rather than dispose of it.


At least one year. Gasoline over a year old is working ok in a BMW i3 REX. It's a hybrid that has a small engine range extender for when the electric charge is low. I hadn't used the gas since last October and wondered when it would be too old to be usable. (It's why I found this question.) I'm intentionally running off gas until the tank is empty so it can be refilled with new. It's not having any problem with it.



  • This really doesn't provide an answer to the question. Even the two links you've posted in your "answer" do not say what you are stating is a good way to go (in fact, like most forums, they have very contradictory information on them). If you have credible sources to back what you're stating, we'd welcome seeing them. Commented Oct 30, 2017 at 0:38
  • It puts a lower bound on the answer, one year. Commented Nov 11, 2017 at 9:16
  • Still, it's just anecdotal forum "evidence" which really means nothing. If you had some verified scientific evidence, it would be more widely accepted as proof of your claims. Commented Nov 11, 2017 at 9:50
  • I found dreamcatcher's answer helpful.
    – rr789
    Commented Jun 19, 2019 at 2:59

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