The Best Marine Fuel Stabilizers for 2021

Nicholas Swartz
Written by
Last update:

Your boat, RV, or jet skis probably cost you a lot of money, right? But have you ever really thought about how much you are spending on your gas?

Luckily, it takes only one little investment and you will never have to worry about your gas line blowing up again! That’s right, I’m talking about a marine fuel stabilizer.

Marine fuel stabilizers are simple products which form a protective barrier around the gas in your fuel lines and prevent corrosion over time. They are small, cheap and easy to install.

We put together the best fuel stabilizers for boats, below.

NameCategoryProduct
STA-BILBest OverallSTA-BIL
STA-BILBudget PickSTA-BIL
K100 MG All-In-One Gasoline Fuel Treatment & AdditiveUpgrade PickK100 MG All-In-One Gasoline Fuel Treatment & Additive

1. STA-BIL

Our rating: 9 / 10

STA-BIL

Check Price on Amazon

Pros:

  • Treatment for up to 320 gallon
  • Prevents corrosion
  • Helps clean fuel system
  • Reduces water deposits
  • Reduces fuel and system deposits
  • Protects against ethanol-related vapor lock irritation

There are several reasons to consider adding STA-BIL 360 Marine Ethanol fuel treatment and stabilizer to your fuel storage system.

Not only does this ethanol treatment ensure years of in-season performance from the marine unit but it also helps prevent corrosion and contains ethanol protection additives that keep ethanol-related vapor lock irritation from occurring.

This keeps the unit running smoothly and the preventative maintenance cost low. For a marine engine running on ethanol, use STA-BIL 360 to keep fuel systems and tanks clean throughout the season.

2. YAMAHA ACC-RNGFR-PL-12 Yamalube Ring-Free Fuel Additive

Our rating: 9 / 10

YAMAHA ACC-RNGFR-PL-12 Yamalube Ring-Free Fuel Additive

Check Price on Amazon

Pros:

  • Excellent Additive
  • Prevents the formation of harmful dissolved gas and also inhibits corrosion
  • Really affordable
  • Has less odor than other brands

Cons:

  • Not every boat or generator is compatible due to differences in fuel water mixture.
  • There are six different sizes of this product available so you would need to select the right one for your needs.

This Yamaha product is designed to be used with gasoline, diesel, or ethanol blended gas. It will work with single and two-stroke engines.

This is an excellent fuel stabilizer fuel treatment that can extend the life of your engine. It does a really good job at ensuring that the mixture water of your fuel is maintained so that in-compatibility doesn’t occur.

We really like the fact that this product doesn’t leave a terrible odor in your boat or generator like some of the other brands.

3. Johnson Evinrude 2 + 4 Fuel Conditioner 16-oz Bottle 0766209

Our rating: 9 / 10

Johnson Evinrude 2 + 4 Fuel Conditioner 16-oz Bottle 0766209

Check Price on Amazon

Pros:

  • Will last a long time
  • Contains a conditioner
  • Has a long shelf life once opened
  • You get your money’s worth
  • Heavy duty

Cons:

  • You need to use a lot of this product for it to work
  • Doesn’t work for all engines

The biggest pro of the Desco 16-oz bottle of fuel conditioner is that it’s a more affordable option compared to the Spectra. In the long run, this product will save you money if it really does what it’s meant to do.

This product has long been used by boat owners and boat owners. Many of them who have used this for years swear that it works miracles! That said, it’s isn’t always recommended by marine mechanics.

Conversely, the 16-oz bottle of fuel conditioner is perfect for smaller boats. We tested it on a three-seat kayak and it did its job. The kayak wasn’t nearly as heavy as a boat of similar size.

4. STA-BIL

Our rating: 9 / 10

STA-BIL

Check Price on Amazon

Pros:

  • 2-year shelf life
  • Prevents fuel from going bad
  • Prevents buildup from the inside of the tank
  • Prevents the fuel system from gumming up
  • Easy to use
  • Non-toxic
  • Safe for use in all engines
  • Maintains fuel at the highest quality on the market

Sta-Bil is a fuel treatment that is highly popular among boating enthusiasts with engines that run on diesel fuel. The performance of a diesel engine is largely affected by the quality of fuel that it runs on, and if you want your engine to run properly this is what you need.

How does it work? Just by adding this fuel stabilizer, your diesel fuel will be empowered with the additive protection that it needs to safeguard it from going bad. It will prevent fuel from going bad for up to a year‡…or more.

5. MERCURY Genuine Quickstor Fuel Stabilizer 12Oz

Our rating: 9 / 10

MERCURY Genuine Quickstor Fuel Stabilizer 12Oz

Check Price on Amazon

Pros:

  • 12oz container will treat up to 210 gallons of fuel
  • Safe for your boat's engine
  • Works with diesel, gasoline, and propane-fueled engines.
  • Protects your fuel from moisture and corrosion

Cons:

  • Keep out of reach of children and animals
  • Boat owners who used it reported no adverse effects

The Mercury Fuel Stabilizer can be added to any new or used fuel. It safely helps protect your equipment against breakdowns and failure due to moisture or corrosion.

This fuel additive is specially formulated with a quick-drying technology for a wide variety of engines and boat types.

This is one of the best marine fuel stabilizers on the market because works without diminishing your diesel fuel's quality.

6. K100 MG All-In-One Gasoline Fuel Treatment & Additive

Our rating: 9 / 10

K100 MG All-In-One Gasoline Fuel Treatment & Additive

Check Price on Amazon

Pros:

  • Check Price on Amazon
  • Stabilizes gasoline for up to 18 months
  • Works with fuel injectors and carburetors
  • Available at different sizes
  • Improves fuel economy
  • Inhibits corrosion and rust
  • Inhibits sludge and varnish build up en fuel system
  • Restores fuel's octane rating
  • Works with gasoline, diesel, and ethanol blends

Cons:

  • Pricey but lasts for 6 months to a year
  • Might cause whitish buildup on injectors

The K100 MG is a premium Marine fuel stabilizer that can be used by those that love boating, small engine powered lawnmowers, motorcycles, or cars.

The main players behind the MG are MG Chemicals, which processes the refined product to take water, stabilizes fuel, and cleans engines and fuel systems.

K100 MG is one of the most popular products in the marine fuel additive industry. It comes in 2 ounce, 4 ounce, and 32 ounce capacities.

7. Yamaha ACC-FSTAB-PL-32 Fuel Stabilizer & Conditioner

Our rating: 9 / 10

Yamaha ACC-FSTAB-PL-32 Fuel Stabilizer & Conditioner

Check Price on Amazon

Pros:

  • Keep fuel fresh for up to 3 years
  • Prevents fuel from gelling, freezing, or becoming water-damaged

(33 Oz)

8. Mercury Quickare Fuel Treatment Additive

Our rating: 9 / 10

Mercury Quickare Fuel Treatment Additive

Check Price on Amazon

Pros:

  • Can be used in gasoline, diesel, oil, or other fuels
  • More hydrocarbon adjustments with octane
  • Reduces emissions and extends engine life
  • Stabilizes fuel better than any petroleum-based solvent
  • Does not contain any mineral spirits or other hazardous volatile fumes
  • Wide range of auto repair applications: gasoline engines, marine engines, generators, pressure washers, lawn mowers, etc.

Cons:

  • Need first to stabilize a tank to prevent rust and corrosion of the tank
  • Can't be used alone, use at least one pint per 30 gallons of fuel

A gas additive that contains no VOC's or solvents is the Mercury Quickare.

Mercury is a name that is familiar to professional, recreational and sports boaters, many professional marinas, and dealers. It is a professional brand of gas. It can work on all gas engines, not just for Mercuory.

Mercury Gas Stabilizer is for both gasoline and diesel engines. It helps clean the fuel before it goes into the engine. It cleans deposits and injector barriers. It also works on the alcohol-blended fuels to keep alcohol from damaging the engine. It keeps the reliability and extends the efficiency life of the fuel.

9. STA-BIL

Our rating: 9 / 10

STA-BIL

Check Price on Amazon

Pros:

  • Costs significantly less than competing products
  • Proven to keep fuel fresh for up to two years
  • Even works in ethanol blended fuels
  • Easy to use

This STA-BIL Fuel Stabilizer comes in a dark blue bottle with measuring lines for easy measuring. You just mix one ounce of this product for every 10 gallons of gasoline.

This STA-BIL product will help stabilize gasoline for a period of up to two years. It’s been proven to help with ethanol blended fuels. The dark blue formula is translucent so that you can see the level of gasoline.

You can use this STA-BIL Fuel Stabilizer by itself or you can use it to top off your gas tank during the winter if you’re worried about fuel freezing.

10. Star Tron Enzyme Fuel Treatment Concentrate

Our rating: 9 / 10

Star Tron Enzyme Fuel Treatment Concentrate

Check Price on Amazon

Pros:

  • Reduces the chances of carburetor icing
  • Works with high aromatic petroleum fuels
  • Has an enzyme cleaner

Cons:

  • You have to re-treat your gasoline
  • If you are using conventional fuel, it might not work well
  • Can increase the volatility of fuels

One thing we really love about this marine fuel stabilizer is that it is not limited to being used just in boats. It can even be used on lawn mowers, generators, and boat engines.

When it comes to fuel stabilizers, it is important for them to be flexible enough and effective, and this one definitely holds up to those standards.

As the name of the product suggests, it will treat the fuel and keep it fresh. It also treats the fuel in a manner that will help when using ethanol blends or octane boosters.

11. CRC 6162 Marine Fuel Stabilizer

Our rating: 8 / 10

CRC 6162 Marine Fuel Stabilizer

Check Price on Amazon

Pros:

  • Stabilizes from -22 to 150 degrees F
  • Prevents fuel deterioration
  • Keeps fuel fresh for up to two years
  • Provides mosquito protection

The CRC Marine Fuel Stabilizer will keep your gasoline fresh. This fuel stabilizer will keep your gasoline fresh from -22 to 150 degrees F and for up to 2 years of storage. It will also inhibit the growth of algae, bacteria, fungus, mold and other microorganisms.

The CRC Marine Fuel Stabilizer is also helps to prevent the development of varnish, gum, and other deposits. It will prevent microbial growth by removing water from the fuel system as well as preventing oxidation and the storage of odors.

This fuel stabilizer will help keep fuels stored in underground tanks from shrinking, waxing, and becoming sticky. The corrosion and rust potential of the fuel will also be reduced as well as being protected from the formation of gums, gels, acid. It will also be protected from valve and carburetor sticking.

12. Sentry New Technology Fuel Treatment

Our rating: 6 / 10

Sentry New Technology Fuel Treatment

Check Price on Amazon

Pros:

  • Simple to apply formula- no storage issues
  • Clear fuel warnings
  • Protects against corrosion
  • Relaxes fuel line
  • Durable product
  • Come with a convenient storage container
  • Small package is ideal for convenient storage, transport
  • Ability to shape up to 10 gallons

Sentry New Technology Fuel Treatment Stabilizes and Eliminates Water in Fuel (Gas Plus) is formulated with a non-hazardous polyamine/polymer, changes liquid water into a soft gel, and then absorbs itself into the void water-free.

It closes off the pores and holes on metals, and restrains rust/mildew from flaking, adhering or making any dust/mist, water absorption, phase change, rusting, oxidation or any corrosion. The gel form will not drain water on the floor, will not become a safety hazard, no dust or any hazard.

It’s ideal for use on gas/petrol containers, including all types of marine fuel, automotive gas, gasoline and diesel. It’s also effective for ethanol-blended fuels and E85 fuels.

Frequently Asked Questions (FAQ)

What is the best marine fuel stabilizer?

The best marine fuel stabilizer is one that meets the needs of the individual caregiver. The reason for this is that the needs of an individual coastline vary significantly. For example, boating in the cold waters of the north Atlantic will obviously be more different in terms of fuel needs than boating in the warm Gulf of Mexico.

Choosing the best marine fuel stabilizer, then, is best done by assessing your own individual situation.

There are, in fact, several things to consider when choosing the best Marine Fuel Stabilizer product. You need to consider which product best fits your fuel needs. As stated above, those needs change depending on your location, use of the boat, and the area that you boating in.

What is the best fuel stabilizer on the market?

When you are operating a boat in or around a body of water, you figure that you will be able to find fuel at a marina or filling station.

Unfortunately, that is not always the case.

Therefore, one of the best investments you can make is equipping your boat with a fuel stabilizer in the event that you run out of fuel on the water. This might be dangerous due to the fact that the engine won’t run without fuel. People have been killed after running out of gas because their engines fail.

What is the best fuel treatment for ethanol?

One of the biggest issues you’ll face with Ethanol blended fuel is that it can be far more corrosive than gasoline and diesel in its pure form.

This can pose a huge problem for any equipment that is sensitive to corrosion.

As far as marine use of Ethanol blended fuels is concerned, you’ll need to make sure you use a marine fuel additive. These additives not only help to prevent corrosion, they also work to keep water out of your fuel tank.

Things can get particularly bad if you are spending a long time on the water. You may be forced to do a lot of swimming.

Do fuel stabilizers really work?

I haven't noticed a difference…

This is a good thing and it's a bad thing.

If they are working, you probably won't notice it. Fuel stabilizers like STA-BIL continue to work for a full twelve months. The problem is that some people only buy STA-BIL – they never even open the bottle.

It's always best to use fuel stabilizers as a preventative maintenance measure. This means that whenever you get gas, remember to always add some fuel stabilizer. It's very rare you'd need to add stabilizer after your first fill up.

You can use the smell of your boat as a litmus test for whether or not STA-BIL is working it's magic. If you are in an area without a strong odor of ethanol (i.e. "gas" smell), then it may be time to add fresh stabilizer.

Conclusion

The best fuel stabilizers may help you prevent problems with your boat in the future without having to make any unnecessary and expensive repairs. Knowing you have that confidence is worth it alone so you can enjoy boating again without worrying about paying for damages.

Our Recommendation

NameCategoryProduct
STA-BILBest OverallSTA-BIL
STA-BILBudget PickSTA-BIL
K100 MG All-In-One Gasoline Fuel Treatment & AdditiveUpgrade PickK100 MG All-In-One Gasoline Fuel Treatment & Additive