Knowing how to store gasoline long-term can be useful for a variety of reasons, especially when preparing for any form of natural or man-made disaster. After all, how else are you going to power a generator for multiple days at a time without a good reserve of gasoline?
Unfortunately, it’s a little more complicated than storing a large amount of gasoline in a plastic 5-gallon container and calling it a day. Doing so will only cause you to end up with a surplus of gasoline that’s going to go bad if you don’t use it within a certain timeframe.
How long are we talking exactly?
Gasoline can begin to go bad in 1-2 months but it typically remains usable for up to 1+ years if properly stored in an airtight container and out of direct sunlight. However, if gasoline is not properly stored then it will go bad much quicker.
Here’s how to store gasoline long-term.
Purchase ethanol-free gasoline and place it in an airtight container, preferably steel. Add fuel stabilizer to the gasoline and leave a small amount of space in the container for expansion. Rotate the fuel supply every year and store it in a cool location that’s out of direct sunlight.
Continue reading if you want to learn more about storing gas long-term.
How to Store Gasoline Long Term
By following the guidelines listed below you’ll have a much better chance of storing your gasoline long-term. Failure to properly follow these guidelines could eventually result in internal corrosion, gummy residue in your engine, and even a damaged engine if the gasoline is that old or badly stored.
Store Non-Ethanol Gasoline
Most of the gasoline available at gas stations is known as E10 gasoline, meaning it’s made from 10% ethanol and 90% gasoline.
What is ethanol?
Ethanol is a form of alcohol known as ethyl alcohol that’s typically produced from corn crops or sugar cane through a process known as plant fermentation. When combined with gasoline it helps to reduce pollution by cutting back on carbon monoxide production.
Unfortunately, ethanol also reduces the performance of gasoline due to alcohol’s ability to attract moisture and because ethanol contains “roughly one-third less energy than ethanol-free gasoline”. Of course, when you consider that ⅓ of 10% only equals out to about a 3% difference in performance, it may not be as detrimental to your engine as many are led to believe.
However, because ethanol is hydrophilic (meaning it bonds to water) it’s going to make your gasoline much more susceptible to attracting moisture through humidity. This results in a shorter storage life that’s about half of what you would expect from ethanol-free gasoline.
The only downside of ethanol-free gasoline is that it’s more expensive than E10 gasoline. But if you plan on storing gasoline long-term it’s certainly worth the extra cost. Go to www.pure-gas.org if you want to find out where you can purchase ethanol-free gas near you.
Use a Steel Gas Can
Investing in steel gas containers (preferably Jerry NATO 5-gallon cans) is a great way to extend the “shelf life” of your gasoline. The problem with plastic gas cans is they’re not good at blocking out air, moisture, and light from entering the container and contaminating the gasoline.
Steel gas cans, on the other hand, are typically built with thick steel walls and a rubber gasket. This means your gasoline will be much better protected from oxygen and moisture entering the container. Both of which happen to be the two main causes of gasoline going bad over time. Steel gas cans will also help to prevent vapor loss and contamination.
However, the benefits of using a steel gas can go far beyond extending the lifespan of your gasoline. For starters, Jerry NATO steel containers are built with a convenient design that allows you to neatly stack them up next to each other. This allows you to store your fuel without taking up too much space.
Steel gas cans are also better suited for warmer environments as the expansion and contraction of gasoline isn’t going to damage steel containers the same way it does plastic. If you’ve ever seen an old plastic gas can that was warped and damaged from being in a hot environment then you’ve seen the result of contraction and expansion first-hand.
Add Fuel Stabilizer
If you plan on storing any type of engine-powered tool or vehicle for a long amount of time (3+ months) then you may want to consider adding fuel stabilizer to your gasoline. The benefit of mixing fuel stabilizer with your gasoline is that it will protect your fuel tank from corrosion and prevent gum and varnish from formulating inside of your engine.
The problem with gum and varnish accumulating inside of your engine (mainly your carburetor) is that it will slowly leave behind gummy, gunked-up deposits that will destroy your motor over time. Fortunately, by simply adding some fuel stabilizer to your engine you will greatly slow down the oxidation and evaporation process that ruins gasoline over time (and your engine). Plus, a small engine that’s been unused for months (or years) will start much more quickly if it’s stored with a fuel stabilizer in its gasoline.
You can also use fuel stabilizer to store gasoline long-term by pouring a small amount in your gas can before you go to fill it up (or after if you’ve already filled the gas container). By doing so your gasoline should now last up to 1-3 years depending on a variety of factors such as heat, humidity, and what type of gas it’s mixed with (E10, E15, ethanol-free, etc).
Leave a Small Amount Of Empty Space In Container
No matter whether you’re storing gasoline long-term or short-term, it’s always important to leave a small amount of empty space left in the container in case the temperature ever reaches a point where the gasoline expands in size. This small amount of empty space could prevent an unnecessary build-up of pressure one day if the temperature ever rises too high.
Another advantage of leaving a small amount of empty space in your gas can (or container) is that it will help prevent spills and overflow as well as reduce the opportunity for condensation to form inside the container. However, having too much leftover space in the container will only allow more air and moisture (oxygen and condensation) to contaminate your gasoline and reduce its lifespan.
That’s why I only recommend you fill your gas can (or container) until it’s about 95% full. This way you’ll have just enough empty space to allow for expansion but not so much that your container will be filled with a pointless amount of oxygen.
Rotate Your Fuel Supply
One of the best ways to ensure you always have fresh gasoline stored at home is to rotate your fuel supply throughout the year. By replacing your gasoline before it goes bad you’ll never have to worry about your engine being ruined from using crummy gasoline.
Now, there are many different ways to rotate gasoline. What matters though is that you replace the fuel with new fuel before it goes bad. How often you’ll need to replace your fuel will depend on the type of gasoline you’re storing (E10 or ethanol-free) and whether you’re using a fuel stabilizer or not.
The only problem with adding fuel additives to your stored gasoline is that it’s going to have to spend more money than you would if you were to simply buy E10 gasoline. However, it might be cheaper to buy E10 gasoline and fuel stabilizer than to buy ethanol-free gasoline.
At the end of the day, it all depends on how long you want your gasoline to last, how often you’re willing to replace it, and how much you’re willing to spend.
Store In a Cool and Dark Location
Now, I know this won’t be an option for many, but if you want your gasoline to last as long as possible then you’ll need to store your fuel in a cool and dark location.
Don’t have a cool location to safely store your gasoline? At least store your fuel in a dark location to avoid the negative effects of UV light. Using a steel gas container can further negate the negative effects of UV light if you truly want to get the most life out of your gasoline.
Storing your gasoline in a dark location will also eliminate direct sunlight from coming in contact with your gas container(s) and raising the temperature of your fuel. So even if you’re not able to store your gasoline in a cool location, at least you’ll be able to prevent your fuel from getting too hot (causing it to break down faster) by storing your gas cans in a dark location.
How Long Does Gas Last When Stored Correctly?
While regular gasoline with 10% ethanol begins to go bad in only 1-3 months, it has a shelf life of over 1+ years when stored correctly. However, there have been many situations where gasoline has lasted up to 2-3+ years when stored out of direct sunlight and in a sealed container such as the gas tank of a vehicle.
However, just because gasoline is usable doesn’t mean it won’t harm your engine. And if you plan on storing gasoline in your vehicle for multiple years then I recommend diluting the old gas with new gasoline before attempting to start the engine for the first time. This will reduce the chance of engine damage and make it much more likely for your vehicle to start.
If you want your gasoline to have a longer shelf life then you’ll need to purchase ethanol-free gasoline. Gasoline without ethanol won’t begin to go bad for 3-6 months and can last up to 2+ years if stored correctly. Unfortunately, ethanol-free gasoline is more expensive than regular gasoline with 10% ethanol. Plus non-ethanol gasoline can only be bought from certain gas stations.
Now, if you truly want your gasoline to last a long time then you’ll need to combine it with a fuel stabilizer. E10 gasoline mixed with fuel stabilizer can easily last over 1-2 years, whereas ethanol-free gasoline mixed with fuel stabilizer can last up to 3+ years before it starts to truly go bad.
How to Tell When Gasoline Is Going Bad
You can tell when gasoline is starting to go bad when its odor changes and its color begins to darken. The smell of gasoline will start to fade to something more sour and foul and the color will transform from a light yellowish hue to a dark golden brown.
If you’re trying to figure out if the gas in your vehicle is going bad you may not be able to see it, but you can still lift the gas cap and smell the gasoline. If you get hit with a strong odor that smells like varnish then the gas has gone bad and should be emptied from the tank before using.
Now, if the gasoline in your vehicle (or any engine) is only slightly old then you can always add fresh gasoline to your vehicle to dilute the older gasoline. This will help to reduce (or effectively eliminate) the harm it’ll do to your engine.
If you’re not sure if the gas in your vehicle is going bad or not you could always turn on the vehicle and look at the odometer to see if the check engine light turns on. All modern vehicles made after 1996 have a check engine light that turns on when the fuel in the tank isn’t burning correctly. Of course, this doesn’t help if the check engine light is already on for something else.
How Much Gasoline Should You Store Long-Term?
The best way to decide how much gasoline to store long-term is to figure out what possible scenarios you want to be ready for.
Do you simply want some extra fuel stored at home in case you forget to fill up one day? Or are you preparing for a power outage and want to be able to power your generator for a few days without having to buy more gasoline?
If you’re the former then you’ll only need a single 5-gallon gas container. However, if you’re the latter then you’ll have to figure out how much gasoline is required to fuel your generator for a single day. Once you’ve figured out that number then multiply it by the number of days you want to be able to power your generator.
Here’s a table to help that showcases how much gas is required to power your generator per hour.
| Watts | Gasoline Used Hourly |
| 5,000 | ¾ Gallon |
| 10,000 | 1 ½ Gallon |
| 15,000 | 2 ¼ Gallons |
According to the table above, a 5,000-watt generator requires 18 gallons of gasoline per day to operate. This means that at the current price of $3 per gallon of gasoline it will cost $54 to power the generator for an entire day. If you want to be able to run the generator for 3 days in a row without stopping it will cost you $162. This does not include the price of the eleven 5-gallon gas containers that you need to store the gas in.
Of course, some people do store their gas in a 55-gallon drum, but that’s up to you if you want to store that much gasoline in one place. Plus you’ll need some type of siphon to get your gas out of it. I recommend the Super Siphon as it’s always worked well for me.
How to Store Gasoline Safely
No matter whether you’re storing 5 gallons or 50 gallons of gasoline, It’s always important to follow proper safety precautions to avoid causing any harm to you, your family, and anything you own near the location where your gasoline was stored.
Here are all the safety tips I recommend following when storing gasoline.
- Store gasoline in a proper gas container
- Store gasoline outside of your home if possible (preferably in a storage shed or fuel storage shed)
- Make sure to avoid spills and inspect for leaks
- Store gas in a well-ventilated and cool area (out of direct sunlight and away from any type of heater)
- Store at least 50-feet away from any ignition source (such as a pilot light)
- Always fill gas containers outdoors and on the ground (never on the back of a pickup truck)
- Never completely fill a gas container to the top (always leave some space for expansion)
- Always keep a B rated fire extinguisher nearby (B is for petroleum and oil fires)
- Store in a location that children can’t see or reach
I also recommend you check your state laws related to gas storage to make sure you’re properly following all your state laws.
