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Adding Fuel Stabilizer To Ethanol-Free Gas: Is It Needed?

Adding Fuel Stabilizer To Ethanol-Free Gas: Is It Needed?

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Paul Brown

I’ve been using ethanol-free gas in my gas-powered yard tools for a couple of years. I recently got to wondering if I should add a fuel stabilizer during the off-season. I’ve done a lot of research on this and here is what I’ve learned.

Do you need a fuel stabilizer for ethanol-free gas? Adding a fuel stabilizer to ethanol-free gas can extend its shelf life and preserve it through the offseason. However, Ethanol-free gas does not attract as much water as ethanol-based gas thanks to the lack of alcohol, so it’s unlikely that you’ll see any benefit unless storing for an extended time.

This article will discuss everything you need to know to blend the perfect premix with ethanol-free gasoline. In particular, check out the tips regarding when to add or avoid stabilizers in the mix. 

What Are Fuel Stabilizers?

Fuel stabilizers are agents that, if added to a fuel tank, create a layer of protection (source). You can add stabilizers to the fuel tank of equipment that is sitting for six months or more but they are not necessary for equipment and engines that are in regular use.

During a storage period longer than two weeks, fuel starts to spoil due to several factors that can affect the quality and, therefore, the usability of the gasoline. If your gasoline has been stagnant for a prolonged period of time, and it is ethanol-based, there’s a decent chance it has begun to spoil.

Ethanol-based gasoline is the quickest to show the effects of spoilage. If you are preparing your premix with ethanol-based gas, you will need to use stabilizers in the mix if you are planning to store the fuel for as little as two weeks. 

The quick spoilage process is due to the ethanol itself. The alcohol will attract moisture. Whether water particles come from within the tank, condensation, or the outside atmosphere, it can be extremely damaging for a 2-engine stroke.

Read Ethanol And The Growing Issue Of Small Engine Problems

Ethanol’s downsides are many, including breaking down residues in the gas tank that are free-flowing in the fuel line and engine which can clog the filter and lead to engine failure (source). However, despite these downsides, ethanol-based gasoline is readily available, as modern legislation in the United States requires that gas has an ethanol percentage of at least 10%.

How Fuel Stabilizers Work

Fuel stabilizers are added to the gas and keep the moisture away from the fuel while preserving it from evaporating. At the same time, such a solution bond with the water particles and absorb them before the fuel has the time to do so (source).

But, if there is no alcohol in ethanol-free gasoline, do you still need to add stabilizer to the mix? It primarily depends on how long you are planning to store your premix or petrol. Adding a stabilizer to the fuel can extend its shelf life to up to 2 years.

Ethanol-free fuel doesn’t suffer from the moisture issues that pump gas does so it is unlikely that you’ll benefit from adding stabilizer unless you are storing it for more than six months.

Read Does Ethanol-Free Gas Go Bad? Fuel Shelf Life Comparisons

Do I Need Stabilizers In A Premix Fuel?

The shelf life of homemade pre-blended fuels should not be longer than a couple of months. Gasoline’s alcohol content, oil quality, and its ability to remain fresh can affect the premix’s shelf life.

Even if you are committed to using only pure, ethanol-free gas, the chances are that once mixed, the oil in the premix will go bad at the same rate as ethanol-based gas would.

Read 2-Cycle Oil Shelf Life: How Long Is Two-Stroke Good For?

If you are after a premix that includes both stabilizer and ethanol-free gas, you should consider buying a commercially-prepared premix fuel like Trufuel (link to Amazon). You get premium gas, synthetic fuel, precise gas-to-oil ratio, and it already includes a stabilizer giving it a whopping 5-year unopened shelf life.

When Can I Use Ethanol-Free Gas Without Stabilizers?

If you have a little reserve of ethanol-free gasoline to use within the next six months, you can store it safely without having to add any stabilizer. Since the fuel does not contain alcohol, it will not attract potentially dangerous water or moisture.

However, in this case, it is essential to store the gasoline correctly in an air-tight container, away from direct sunlight, 15 meters away from any potential spark sources, and at room temperature.

While water is the leading cause of damage, exposure to a drastic temperature change and heat sources can lower the quality and usability of the gas in no time.

And one more thing. While ethanol-free gasoline is suitable for use after six months without having to add stabilizers, you should blend the oil and gas only two weeks before the date you are planning to use your equipment.

Keep in mind that, while the gas might still be usable, the oil will lose viscosity and lubrication power over time, so the mix will not be efficient.

Read Does Premix Fuel Go Bad? HomeMade Vs Commercial Gas-Oil Mix

When Do I Need Stabilizers For Ethanol-Free Gas?

If you are planning to store your weed eater and leaf blower through the winter with fuel in the tank, you might consider adding a stabilizer to the ethanol-free gas. Honestly, though, a better option is sometimes to store it with an empty tank and burn off any fuel in the carburetor.


If you are after a product that contains only pure non-ethanol gasoline, yet has a shelf life of over two years, buying a pre-blended fuel might be the answer. I switched to commercially-prepared premix fuel for all of my 2-stroke yard tools. It saves time and I never have to worry about the age of a sealed can sitting on the shelf in my shop.

I’ve heard people complain that premix fuel is expensive and I have addressed that in a previous article (click the link to read that article). The bottom line though is that premix fuel from a manufacturer offers a lot of benefits, including:

  • Ashless, residue-free oils
  • Synthetic oils
  • Ethanol-free gas
  • Stabilizers
  • Extended shelf life

These bottles also come in ready-to-use containers that allow you to get the job done in no time and without any wastage. They are precisely mixed to match the gas-to-oil ratio of your 2-stroke.


Whether to use fuel stabilizers in ethanol-free gasoline or not is a subject that mechanics and consumers have been discussing for many years. Ultimately, it depends on how often you are making use of your equipment and on how long you intend to store the fuel.

I’ve heard people say that by always adding a stabilizer in ethanol-free gas, their outdoor equipment would always start immediately, after a season or even a year of storage.

Of course, manufacturers often suggest using only gas that is less than six months old. The problem is, it can be hard to find ethanol-free gas at your local fuel station or convenience store. 

But a valid alternative is to just buy pre-blended fuels. These products enhance the performance of your equipment while guaranteeing the perfect gas-to-oil ratio.

Store-bought premix already includes stabilizers, synthetic oils, ethanol-free gas, and have a shelf life longer than two years. Personally, I’d rather spend my time using my equipment than preparing fuel mixtures.