Leaving Gas in Generator- A Threat To Life

Using a generator can sometimes be very unpredictable. Most of the time you do not need it but during a sudden electricity outage, you use the generator. There is always some fuel or gas present in the generator, which may or may not be safe depending on how long it is present in the generator.

How long can you leave gas in a generator?

A gas generator’s tank could contain approximately 1 to 2 gallons of gasoline on average. In the tank of a gas generator, gasoline can last up to 6 months. However, including a stabilizer chemical in your gasoline can extend its life by up to a year or more.

If you own a gas generator, you should be aware of how to use it properly. you should have extra gas and fuel supplies at your home.

What are the risks of leaving gas in a Generator?

Gas is essential for the normal working of a generator, but how much should be the gas level or how old the gas is in the tank, directly affects the functioning of the generator.

Following are the potential hazards of leaving gas in the generator:

  • Oxidation

When metal comes into touch with water, it undergoes oxidation, which is the same process that causes it to rust. This is also true with gasoline, particularly ethanol, which could damage the quality of the fuel.

For stationary units, a 250-gallon propane tank can last up to 8 to 15 days. A gasoline unit, on the other hand, must be turned off and allowed to cool before refueling. Splashing gas on a running generator’s hot exhaust, near the spark plug, or elsewhere might quickly ignite a fire.

  • Microorganisms

Your generator gas tank could be a hub to many different microorganisms and bacteria. Microorganisms may be able to survive in ethanol gasoline that has been upgraded.

It is the ethanol itself that lures them inside. These microorganisms will excrete highly acidic excretions that may cause corrosion in the fuel.

  • Absorption of water

Hydrophobicity is a property of gasoline. This signifies that gasoline is averse to contact with water. Ethanol gasoline is hygroscopic, which means it absorbs water from the air.

This essentially means that gasoline does not want water to be added to it, yet it cannot avoid it since water molecules are drawn to it.

The fuel will be unaffected in a limited percentage of cases. However, Phase Separation will occur in large quantities. The gasoline will rise to the top, while the water will accumulate to the bottom. Once the water starts pouring on the inside, this simple operation may ruin the tank and its engine.

How to store generator when not in use?

Generators are mostly not in use, except in an emergency conditions. In normal conditions when not in use, it is essential to store your generator in the right way.

Follow the steps given below to store your generator for a long time.

  • Check the gas or fuel level:

If your generator is in good condition and has no leaks, it will not consume a lot of oil or gas. However, you should check and replenish up the fuel levels before putting them away. This will just be a few tablespoons for most generators.

Consult your generator manual if you’re not sure how to check your oil levels.

  • Check out the annual maintenance:

Although generators are very low maintenance, a little annual maintenance will help them last longer. Make this annual maintenance a priority at the start of hurricane season to avoid problems when a storm approaches.

Following are the two steps that you must take:

  • Remove the spark plug and replace it.
  • Replace the air filter as needed.

Both these activities are simple enough, and instructions should be included in your owner’s manual.

  • Empty the gas tank or add stabilizer in it:

Ideally, you should drain outgas before putting the generator aside. You do not want to keep your generator with flammable gasoline in the tank.

You will need to put a fuel stabilizer to a full tank of gas in the generator if you cannot run it to empty. The fuel stabilizer keeps the gas from gathering moisture and spoiling in the tank. It will help keep the fuel from degrading your generator’s rubber and plastic parts.

Related questions

Is leaving gas in a generator a bad thing?

It is usually best to store your generator without any gasoline in it for long periods of time. Although removing the gas is strongly advised, if you apply a stabilizer to prevent corrosion, you can store the generator with the gas inside.

How do you keep gas in a generator for a long period of time?

It is usually best to keep your generator without any gasoline in it for long-term storage. You could transfer the gas to your car if you do not want to run the generator till it is empty for the sake of burning gasoline. Most generators run on the same sort of gasoline as cars (normal, unleaded).

How long does it take for gas in a generator to go bad?

A decent fuel stabilizer can extend the life of the generator gasoline you are storing by two or three times. Preppers will tell you that unadulterated diesel fuel can last for roughly a year if kept properly.


It is best to store your generator without any gas or fuel to increase its efficiency and lifespan. In case, you do not want to discard the gas, you can follow the guideline mentioned above.

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