Estimated reading time: 6 minutes
The images of people waiting in long lines at the gas station after the recent Colonial Keystone XL pipeline cyberattack were a stark reminder of our dependence on gasoline. Even though electric-powered vehicles are on the rise, we still rely heavily on our gas-powered vehicles and equipment.
Some people even took leave of their senses during the crisis and pumped gas into plastic bags and other unsafe containers. Although industry experts admitted that panic-driven hoarding contributed to fuel shortages much more than the actual shutdown, the whole situation brought up an interesting question: How long can you store gasoline?
Unfortunately, there is no straightforward answer to the question since standard gasoline is a mix of several components that can split apart, change, or evaporate over time. For example, whenever gas is exposed to air and water, it will slowly begin to oxidize.
Standard gasoline usually begins to go bad after about 30 days. However, just like the date on your milk carton or medical prescription, it’s not an all-or-nothing kind of situation when it comes to the calendar. Gas will not suddenly become unusable; its efficiency degrades slowly, eventually coming to the point that it may harm your engine.
Let’s look at some ways you can boost those 30-plus days of freshness.
Gasoline in the engine of a car that you drive regularly burns up before it has the chance to degrade. However, if you want to store gas for long-term use or worry about the gas in a mower stored over the winter, you should consider using a fuel stabilizer.
Fuel stabilizers—which are available online, in automotive stores, auto sections of big box stores, and at gas stations—are a mixture of lubricants and antioxidants that are designed to limit evaporation and repel water.
Most of these mixtures will preserve fuel for a year or more. Here are the steps for using a fuel stabilizer.
- Add measured stabilizer to a nearly empty gas tank. Since products can vary, read your product label for the correct amount of stabilizer for your size tank.
- Fill your tank with gasoline.
- Run the engine for 5 to 10 minutes, allowing the stabilizer to reach the entire engine.
After 12 months or so, if you haven’t used the stored gas, you can add another dose of stabilizer for another year of protection.
Use and Replace
Like the familiar emergency food pantry rule of “first in, first out,” another way to increase your gas storage time is to follow the use and replace the storage method.
Instead of waiting until your gas tank is nearly empty before getting a fill-up, you could top it off with the oldest gasoline you have stored at home. Then, take the gas can you used to the station for a refill. Once you get into a rhythm, you’ll seldom have gas on hand that is more than a few months old.
Now let’s go back to those horrifying images of people pumping gas into plastic grocery bags. You no doubt realized that was dangerous (and stupid), but maybe you don’t know just how dangerous improperly stored gas can be.
They don’t put those warning signs on gas pumps for decoration. Gasoline is a highly flammable substance, and even its vapors can lead to deadly explosions.
Here are some rules for storing and transporting standard gasoline.
- Store the gas in lidded containers of five gallons or less that have been approved for gasoline. These containers will have a label designating they are designed for petroleum products. Never store or carry gas in plastic bags, milk jugs, glass jars, or other unapproved containers.
- At the pump, aim to fill the gas containers no more than 95 percent full to allow for some expansion.
- Replace the container cap, making sure it is screwed on tightly.
- Store the container in a shed or other outbuilding away from the house and out of direct sunlight.
- Make sure you place the container at least 50 feet away from a water heater, space heater, furnace, or other heat sources.
If your vehicle and equipment needs require you to store more than a few gallons at a time, you also can store gas in 30-gallon or 55-gallon drums. If you go this route, you’ll need to make sure the drums are approved for gasoline storage and are completely dry before you fill them. Then, leave them tightly sealed until you plan to use the gasoline. Invest in a good drum pump for when it comes time to use the fuel.
Keep in mind that a partially filled drum is more likely to degrade through condensation and evaporation. And, because of their extreme flammability risk, keep fuel drums at least 50 feet away from your home, garage, and any heat sources.
How do you know if gasoline has gone bad?
Especially if you have more than one container of gas, don’t trust your memory. Label all of your containers with the date you filled them.
Other than keeping track of how long you’ve had the gas, it is hard to identify its age. However, there are some telltale signs of “bad” gasoline. One is when your engine is not running smoothly. Since the chemical properties of gas change as it ages, your car may not be able to process old fuel. You may see your “check engine” light go on, or you may notice hesitant ignition, poor acceleration, or rough idling sounds.
Gasoline also changes in appearance and smell as it ages. It may be darker in color and have a different smell than that distinctive gasoline odor. Some people report that old gas has a sour or spoiled smell.
When in doubt, pour a little out into a clear jar and examine its color and odor. If it still looks mostly clear and smells like gasoline, it’s probably still fine to use.
However, it will be necessary to remove bad fuel from your gas tank to avoid serious engine problems in some cases. In other cases, filling up the tank with fresh gas can solve the problem.
Despite what you saw in the photos of people with dozens of containers in the back of their trucks during the recent East Coast pipeline crisis, more is not always better when it comes to gasoline.
It may be difficult to keep large quantities of gas treated and ready to use. Just as with other emergency supplies you aim to have on hand, it’s a good idea to rotate your stock. And a final tip is to keep your vehicles’ gas tanks on full as much as you can. That way, you won’t have an immediate worry about running out of gas during a short-term crisis.