What is the Best Fuel Stabilizer for Generator

If you’re reading this article, then you’ve likely experienced filter clogs in your generator fuel system. This problem becomes worse when you store your generator for long periods. To ensure that your generator runs smoothly, you need a fuel stabilizer for generator.

That being said, there has been a lot of discussion about the best fuel stabilizer for a generator. This is because there are so many products on the market, each claiming to be the best. Moreover, different types of generators work best with specific brands.

As a result, comparing all these factors leads to confusion regarding product selection.

It is, therefore, necessary to have a guide as to which are the best fuel stabilizers for generators. The article enumerates two of the best fuel stabilizers for generators so that you can make an informed decision.

But first thing first……

What is Fuel Stabilizer?

Fuel stabilizers are products that help keep fuel fresh and usable. They work by preventing oxidation, which causes gas to go stale. By keeping gasoline fresh, a stabilizer can ensure that an engine starts faster after sitting idle over winter or in storage.

It also prolongs an engine’s life and protects carburetors, fuel injectors, and other engine parts from corrosion.

How Does Fuel Stabilizer work?

Fuel stabilizers keep fuel fresh and stable to burn more cleanly, efficiently, and completely. They do best when stored in a cool, dry location with limited exposure to light.

So how do they work, anyway?

There’s a complicated chemical process involved here, so we’ll try to keep it simple.

Both oil-and gas-based fuels have molecules that move around freely in any given tank of gas. However, when you stop using your generator, the molecules deteriorate over time. As a result, it can lead to all sorts of problems with engine performance after a prolonged period of sitting still.

When exposed to air for too long, specific molecules break down into an acid compound that corrodes metal surfaces within your engine and deposits sludge on moving parts. By pouring in a stabilizer before storage, you add hundreds or thousands of polymers into your gasoline.

These large polymer chains then sit on top of each molecule as it loses its structure over time, preventing decomposition and corrosion from taking place. The result is a stable generator that’s ready to use when you pull out of storage.

You don’t need to use a fuel stabilizer every time you refuel. Doing so will cause buildup in your tank. Instead, look at using one whenever you store your vehicle for an extended period.

Recommended Amount of Fuel Stabilizer for a Generator

The rate at which you’ll need to put stabilizer into your fuel tanks depends mainly on how often you use your generator and climate.

If used heavily and regularly, you will have to add a stabilizer more frequently perhaps once every month or two. In contrast, if it’s rarely used, you can probably make it six months before needing to inject some more liquid into your generator tank.

Similarly, a backup power source in colder climates will require a more significant amount of fuel stabilizer to prevent the formation of ice crystals that can clog carburetors and lead to costly repairs.

However, most generators require 1 ounce of fuel stabilizer per 2.5 gallons of gasoline. The average capacity for a generator’s tank is between 10 and 30 gallons, though those figures highly depend on the generator’s make and model.

All in all, ensure you check your owner’s manual for recommendations specific to your generator models or consult a professional.

How Long Does Fuel Stabilizer Last

What is the Best Fuel Stabilizer for GeneratorAs we’ve noted, fuel stabilizers can extend your gas supply by keeping fuel from going bad. But how long does a bottle of fuel stabilizer last, exactly? And do they expire? Do they lose their effectiveness over time or when exposed to heat or light?

As it turns out, stabilizers’ shelf lives are dependent on two primary factors; the product type and optimal conditions for storage.

So, to prolong fuel stabilizer shelf life, there is a list of specific storage conditions on each product label you’ll want to keep in mind:

  • Store from direct sunlight in a cool, dry place (not exceeding 105°F or 40°C) with a tightly closed lid.
  • Remember not to store fuel stabilizers above petroleum-based products, such as motor oil and antifreeze.
  • To avoid contamination, keep fuel stabilizers away from any strong chemicals, like cleaners and detergents.
  • Do not mix old fuel stabilizers with new products, especially if different manufacturers make them. The results may be unpredictable at best and could prove hazardous at worst.
  • Use your fuel stabilizer within its stated shelf life (found on the container). After that date has passed, you should dispose of any unused gas additive or use it per the manufacturer’s directions.

Therefore, ideally, you should expect a fuel stabilizer to last at least one year and up to two years if the above conditions are maintained.

Can You Put Fuel Stabilizer In a 2 Stroke Engine?

What is the Best Fuel Stabilizer for GeneratorA 2 stroke engine doesn’t rely on oil to lubricate its moving parts but instead depends on gas and oil mixing at the correct ratio.

Nonetheless, if you have a two-stroke engine in your generator, it’s okay to put a fuel stabilizer in your tank.

Just remember: Always check your owner’s manual before adding anything to your engine.

Best Fuel Stabilizer in the Market

To assist you in finding the best fuel stabilizer for your generator, we’ve reviewed two of the best fuel stabilizers on the market today, highlighting their specs, features, pros, cons, as well as where you can buy one.

1. Star Brite Star Enzyme Fuel Treatment

One of our top picks for fuel stabilizers is Star Brite’s Star Enzyme Fuel Treatment.

This product is specifically designed to keep newer engines running smoothly and efficiently. It eliminates the rough idle and hesitation associated with today’s ethanol-blended fuels.

Since it does not contain alcohol or other harmful solvents, Star Brite can be safely used in all gasoline and diesel applications without worrying about storage tanks or lines contamination.

Additionally, it features a proprietary blend of enzymes that help eliminate exhaust odors caused by partially burned fuel left in your engine. This improves performance while extending engine life, power, and performance.


  • Manufacturer: Star Brite
  • Product Dimensions: 8 x 3 x 2 inches
  • Sizes Available: 8 oz
  • Applications: 2-cycle & 4-cycle
  • Item Weight:1 ounces

Key Features

1. Multiple Size Choices

One thing to love about Star Brite is that they offer a range of sizes to best fit your needs. Their smallest size comes in a six-ounce bottle (weighing only one pound), while their largest size, which weighs 16 pounds, is a whopping five times bigger.

With such a wide variety of options, it’s never been easier to find what you need.

2. Pre-diluted

Enzyme Fuel Treatment is pre-diluted for gasoline, diesel, and oil. No measuring, no mess. Great for small engines, lawnmowers, generators, and boats. The environmentally friendly and biodegradable formula leaves no residue or oily film on top of water tanks.

3. Incorporate Enzyme Technology

Star-Brite is one of only a few producers globally that utilizes an enzyme in its formulation.

When incorporated into a fuel stabilizer, they will ensure that your gasoline doesn’t go bad while you store them.

The enzymes break down soluble gums and sediments in an emulsion tank to keep water out of your engine’s combustion chamber and help stop corrosion in its tracks.

4. Two-Year Shelf Life

Extremely stable and long-lasting, you can store it in a cool, dry place for two years or more. There is no need to worry about keeping track of dates or throwing away partially used containers.

It won’t lose any potency during that time. This makes it highly cost-effective since you only buy it once and then re-use it over and over again.

5. Compatible with Two and Four Cycle Engines

With its unique formulation, Star Brite can be used on both two- and four-cycle engine systems. Furthermore, the stabilizer can easily be integrated into any current or new engine that requires cleaning and care. Its single-use package eliminates measuring mistakes, while its quality ingredients ensure perfect consistency and dosage each time you use it.

The user simply needs to read their product label before use for instructions.

6. Environmentally Friendly

The active ingredients in Star Brite’s enzyme are derived from a renewable source, enabling it to be more environmentally friendly than other fuel treatments.

Since it is entirely organic, there is no risk of clogging your boat’s engine. In addition, the stabilizer contains no harmful heavy metals such as zinc and cadmium that can wreak havoc on your boat’s engine.

What We Like

  • It helps reduce smoke and all other emissions from your engines
  • Stabilizes gas for up to two years
  • Increases power, acceleration, and overall performance
  • Reduces harmful emissions like carbon monoxide, nitrogen oxides, and hydrocarbons
  • Available in multiple sizes to fit your needs

What We Don’t Like

  • Expensive compared to other stabilizers of the same category

Where to Buy

After going through all the reviews, you might be wondering where’s a good place to get a deal on a star enzyme fuel treatment. Well, one place that you might want to check out is Amazon. The online retailer is easy-to-use and has an outstanding reputation for customer service.

As a result, if you respond promptly, you can save money as well. It’s also worth noting that Amazon provides free shipping, which means there are no hidden costs or fees. Alternatively, visit their website or any authorized dealer in your locality.

2. Sta-Bil Storage Fuel Stabilizer

Next in our list of the top fuel stabilizer brands to ensure peak performance and life of your engine is Sta-Bil Storage Fuel Stabilizer.

This product works to keep your fuel fresh while also preventing corrosion and oxidation, ensuring your machine runs smoothly even after long periods of non-use. What’s more, the formula is ethanol-free and safe to use in both two and four-stroke engines.

And though made explicitly for the marine industry, this product can be used anywhere, from lawnmowers and cars to generators or snow blowers.

And when used according to the engine manufacturer’s instructions, the Sta-Bil fuel stabilizer keeps fueling fresh for a longer time.


·      Brand: ‎STA-BIL

·      Product Dimensions: ‎14.13 x 10.5 x 9.56 inches

·      Sizes Available: 16 oz

·      Applications: 2-cycle & 4-cycle

·      Item Weight: ‎15.4 ounces

Key Features

1. Alcohol-free

 Sta-Bil does not contain ethanol, which could corrode plastic gas tanks and fuel lines. If a small amount of ethanol is used in your machine’s fuel tank and fuel lines, it may cause deterioration to occur more quickly.

As a result, it allows them to be used in any application requiring a safe, adequate water removal product.

2. Compatible with all fuel types

The product can be used with all fuel types, including gasoline, diesel, natural gas, and propane. It offers reliable protection for gasoline stored in both standard and portable containers. No matter what type of fuel you use or where you store it, you can count on Sta-Bil to stabilize it safely for long-term storage.

3. Multiple size choices

Sta-Bil comes in single and five-gallon sizes and can treat up to 250 gallons of fuel. The size you need depends on how much fuel you want to protect.

4. Compatible with all gasoline engines

When it comes to Sta-Bil fuel stabilizers, compatibility is something of a necessity. You don’t want a product that will only work on certain engines; you want one that works with everything.

With Sta-Bil, there are no exceptions. This product was designed for use in all gasoline engines—meaning you won’t have to stress about whether or not it will perform as advertised when it counts most.

5. Two-year shelf life

Sta-Bil’s technology provides for guaranteed two-year shelf life. This means that you can count on Sta-Bil to protect your stored fuel no matter how long it has been since you put it in storage. You will never have to worry about its effectiveness, regardless of how long it sits unused.

What We Like

  • Extends gasoline storage life for up to 2 years without sacrificing performance
  • Prevents costly repairs to engines by eliminating harmful contaminants
  • Safe for use in all size-gasoline engines
  • Reduces the need to drain and refill fuel tanks

What We Don’t Like

  • Several reviewers complained that containers were mislabeled
  • The bottle design makes it difficult to drain the stabilizer

Where to Buy

Sta-Bil Fuel Storage stabilizers are available at most auto parts stores and major online retailers like Amazon. More information is also available on Sta-Bil’s website. 

Faqs About Fuel Stabilizers

1. Do I need a fuel stabilizer for my generator?

Absolutely. Even if you store your generator indoors, it’s still susceptible to moisture and other elements. Adding a fuel stabilizer to your gasoline can cut down on corrosion and keep your equipment running at peak performance when you need it most.

2. When should I use a fuel stabilizer?

Use a fuel stabilizer if you plan on storing your generator for an extended period. Run your generator with stabilized gas after adding a fuel stabilizer. Allow your generator to rest for about four hours after you’ve filled it with stabilized gas before turning it off and storing it.

3. What does a fuel stabilizer do?

A fuel stabilizer reduces and prevents the oxidation of fuels stored over time. Oxidation occurs when fuel is exposed to air, which causes it to break down and form harmful acids that collect on engine parts. This leads to clogged filters, damaged cylinders, weak emissions, and poor performance.

4. Is a stabilizer good for a generator?

Generators run on gasoline. Gasoline is a highly combustible liquid that is volatile when kept in storage and especially unstable when left unused. To ensure that your generator runs as it should, it’s essential to use an appropriate fuel stabilizer to treat your fuel and keep it fresh.

5. What happens if you leave gas in a generator?

If you leave gas in a generator, it can expire in two ways. One is through evaporation. When exposed to air, fuel slowly evaporates from your container into your engine, where it could seriously damage its operation.

The other way is through oxidation. This process occurs when chemicals in your fuel react with oxygen present in air or water. Oxidation can lead to water contamination which clogs up your equipment.

6. Can I put a fuel stabilizer in old gas?

When you put a fuel stabilizer in old gas, it doesn’t restore it to its original state. Although some stability additives break down specific gasoline components, they don’t make your old, stale gas fresh again.

Instead, they prevent further degradation while the mixture ages for a few more months or years in your storage tank before usage.

7. Is it better to drain the gas or use a stabilizer?

Both methods work well, but adding a stabilizer while filling up ensures that it coats all the little pieces of debris and sediment on your fuel line.

Draining gas, on the other hand, leaves behind any gunk stuck in your fuel filter. Over time, these particles can clump together and clog up essential elements of your carburetor or fuel pump.

8. How do you fuel a generator stabilizer?

First, fill your stabilizer according to its instructions. Using your siphon pump or manual siphoning, add one ounce of stabilizer per 2.5 gallons of gas.

Second, let the engine run for about 10 minutes to mix and distribute itself. Lastly, shut off your generator and allow it to cool completely before storing it.

9. How long does gas with stabilizer last?

The shelf life of gasoline without a stabilizer is unlimited. If stored in a dark, cold place and well-sealed against air, fresh gasoline with the best stabilizer, such as Briggs and Stratton 100119 Fuel Stabilizer, has a shelf life of around three years.

10. How much STA BIL is in a gallon of gas?

There is 1 ounce of STA BIL in 2.5 gallons of gas. The amount varies depending on how many fuel additives you’re using and how much sludge your motor produces. If your engine has sludge, then add an extra ounce of STA BIL to your existing 2.5 gallons to compensate for it.

11. Can two stabilizers be connected together?

Most experts say no. Mixing fuel stabilizers or having more than one type of stabilizer in your tank will cause all sorts of problems, including issues with engine performance, clogged filters, and other expensive problems. Stabilizers are designed to work independently; they shouldn’t be mixed.

12. Do fuel stabilizers have side effects on my generator?

Fuel stabilizers are made from primarily non-toxic chemicals and additives, though some do have small amounts of alcohol in them. There are no side effects from these products unless you ingest them or get them into your eyes. If any spilled product ends up on your skin, wash it off with soap and water.

13. What is the shelf life of a stabilizer?

Fuel stabilizers, on average, last two years after opening the bottle. However, this is dependent on several conditions, including storage and the volume of product consumed over those two years.

If the container hasn’t been opened, though, you can keep your stabilizer for up to 5 years. However, it would be excellent to consume it before the expiration date or best before the date.

14. What type of stabilizer should I use in my generator?

The type of stabilizer to use in my generator depends on what kind of fuel you will be using and how often you will be using it.

Diesel fuel is much more stable than gasoline if you run your generator more frequently. This means that some stabilizers designed for use with gasoline-powered generators won’t work with diesel; we recommend looking into those specifically designed for engines intended to operate on diesel.

Bottom Line

With the overwhelming data now at your fingertips, there is no excuse for your generator engine to stop working.

We are aware that the permutations of fuel stabilizers are numerous and can be confusing, especially when you have hundreds of products available to choose from.

If you are looking for the best fuel stabilizer for the generator, consider our selection. They’re all reliable, have excellent reputations, and are considered safe for most generators.

Check out the video for more

About Steve Stuart

Steve Stuart is an electrical engineer who developed interest on generators during his school years. After school, he became a generator enthusiast. This is after encountering power supply problems at the area of residence where he lived. Power would be on and off and so food would go bad and the room heater would go off especially during winter. After trying the different generator brands for several years, Steve now provides information on the available brands and products in the market today. Based on his experience, he gives the do’s and the don’ts when it comes to generator use.

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