Best Fuel Stabilizer For Boats

Best Fuel Stabilizer For Boats To Protect Your Fuel System

Best Fuel Stabilizer For Boats

Best Fuel Stabilizer For Boats

When we put fuel in our boats something we don’t think about is the negative effects that the fuel has on our boat’s fuel system. Ethanol is a powerful solvent, powerful enough that it can dissolve fiberglass fuel tanks. It also reacts to fuel filters and carburetors, certainly, it does more harm than good in your boat’s fuel tank. This is why we decided to write about the best fuel stabilizer for boats.

A lot of us don’t have the luxury of using the boat fuel stations offered on major lakes and marinas, which are stocked with ethanol-free fuel. So, we fill our boats up at the same gas stations we use to fill our vehicles.

Fortunately, marine fuel stabilizer can combat the effects of ethanol and help make fuel more friendly to our boats. But, not all fuel stabilizers are created equal, some get the job done and some leave a lot to be desired. Below we’ve reviewed 6 of the best marine fuel stabilizers, to help you choose a product you can rely on.

Comparison To Get The Best Fuel Stabilizer For Boats

Fuel Stabilizer  Duration Fuel Quantity Treated by 32 oz. Check Price On Amazon
STA-BIL 360 Marine with Vapor Technology .

2 years

Up to 320 Gallons Check Price On Amazon
Sea Foam Marine Motor Treatment for gas and Diesel Engine 2 years Up to 32 Gallons Check Price On Amazon
Star Tron Enzyme Fuel Treatment 2 years Up to 512 Gallons Check Price On Amazon
Sentry New Technology Fuel Treatment 2 years Up to80 Gallons Check Price On Amazon
Bell Performance – Mix-I-Go Concentrate Unknown Up to 320 Gallons Check Price On Amazon
PRI Fuel Stabilizer 3 years Up to 512 Gallons Check Price On Amazon
MERCURY Quickstor Fuel Stabilizer 1 year 160 Gallons Check Price On Amazon
Yamaha ACC-FSTAB-PL-32 1 year Up to 96 Gallons Check Price On Amazon

Features Of The Selected Fuel Stabilizers For Boats

Here we selected the eight possibly best fuel stabilizers for boats use:

  1. STA-BIL 360 Marine with Vapor Technology
  2. Sea Foam Marine Motor Treatment for gas and Diesel Engine
  3. Star Tron Enzyme Fuel Treatment
  4. Sentry New Technology Fuel Treatment
  5. Bell Performance – Mix-I-Go Concentrate
  6. PRI-G Fuel Stabilizer
  7. MERCURY Quickstor Fuel Stabilizer
  8. Yamaha ACC-FSTAB-PL-32

STA-BIL 360 Marine with Vapor Technology

Sta-Bil is a popular brand, for good reason. Their 360 Marine version of fuel stabilizer features vapor technology.

The product creates its own vapor, designed to rise above the fuel level and offer its protection, combating the damaging effects of ethanol vapors where other fuel stabilizers can’t reach.

It also helps clean residue left behind and prevents your fuel system from becoming clogged, or corroded.STA-BIL 360 Marine With Vapor Technology.

It is not recommended for storage use over 90 days, after this time frame, the effects of this stabilizer will be jeopardized.

Its ability to preserve the fuel structure and protect your engine will be ineffective. So, if you’re planning to overwinter your boat, this may not be the best choice.

STA-BIL has some more options to fulfill our needs. For example, STA-BIL fuel stabilizer for storage protects the fuel for up to 24 months in storage.


  • Vapor Technology
  • Made in the USA
  • Rust Protection


  • Not recommended for fuel storage

Sea Foam Marine Motor Treatment For Gas And Diesel Engine

This EPA registered product is used for all gasoline and diesel engines. The product is good for all types of motor oils, synthetic or conventional.

We can use Sea Foam motor treatment for fuel storing as it stabilizes the fuel for up to 2 years. It prevents the stored fuel from evaporation, vapors, and from the formation of varnish or gum.Sea Foam Auto Marine Fleet Motor Treatment

It keeps the whole fuel system clean and well lubricated. Normally for general maintenance one ounce is enough for each gallon of fuel but, in the case of cleaning the system, we should use 2 ounces or more per gallon of fuel.

In my opinion, this Sea Foam product is the best fuel stabilizer for boats because of its versatility.


  • The versatile product cleans and lubricates the full fuel system with care
  • Suitable for all diesel and gasoline engines
  • Contains petroleum-based ingredients that are not harmful at all for engines or parts of the fuel system.


  • One ounce treats only one gallon of fuel.

Star Tron Enzyme Fuel Treatment

Star Tron’s fuel treatment works by breaking down impurities and sludge in fuel and preventing separation that can cause poor fuel performance and varnish residue.

The grime is then safely burned away with the gas as you use your boat. Star Tron is a good choice for use when overwintering, or storing your boat for a prolonged period of time. It can help fuel keep its integrity and prevent ethanol damage for up to 2 years.Star Tron Enzyme Fuel Treatment

It is not a marine-specific fuel stabilizer, so it is lacking the higher grade water absorption ability of strictly marine types.

However, it is still a quality product and will help your boat’s fuel system work better, for longer.


  • Stabilizes Fuel Up to 2 Years
  • Prevents Fuel Separation
  • Can Help Rejuvenate Old Fuel


  • Not Specifically for Marine Use

Sentry New Technology Fuel Treatment

Sentry’s new gas plus formula is one of the best fuel stabilizers on the market. It is not marine-specific, but it does have the stronger water eliminating effects of brands marketed specifically for marine use.

It stabilizes, cleans, and prevents fuel lines from freezing up. It can be used in your tank before storage and during every fill-up. It can be used to restore quality to old fuel and it can boost mileage.Sentry New Technology Fuel Treatments

It comes at a steep price and is significantly more expensive than its competitors. We can’t deny the quality of this product, but the price is a little deterring.


  • Inhibits Line Freezing
  • Cleans and Protects
  • Maximum Strength


  • Expensive

Bell Performance – Mix-I-Go Concentrated

Bell Performance Mix-I-Go formula is concentrated 1 ounce treats up to 10 gallons of fuel, making this product convenient to use every time you fill-up. This product has been around for a long time and it has proven its reliability in being a good fuel stabilizer. It prevents ethanol breakdown and removes water from gas just as well as its fancy competitors.Bel erformance MIX-I-GO Concentrated Gas Treatment

It is not marine-specific, but it can be used in boat tanks. It is not recommended for fuel storage, but it can be used to help bring quality back to old fuel. Overall this product is a diamond in the rough, and a little goes a long way.


  • Concentrated
  • Boosts Performance


  • Can not be used to store fuel
  • Not marine Specific

PRI-G Fuel Stabilizer

PRI has almost all the bases covered with their Fuel Stabilizer. It cleans, prevents ethanol damage, and stops fuel breakdown for up to 3 years. It also contains no alcohol and improves fuel efficiency. Whether you’re storing your boat or using it for the weekend, PRI is a good choice. It is a quality product that will get the job done every time.PRI-G Complete Gasoline Treatment

It is not marine-specific but offers the same benefits as products marketed for marine use. It won’t bring old fuel back to life though. We don’t recommend using this product in E-10 Fuel that has been sitting longer than a month or two, while it prevents separation, it won’t promote remixing.


  • Stabilizes Fuel Up to 3 Years
  • High Concentration
  • Good Price


  • Not Marine Specific
  • Can’t Bring Quality Back to Old Fuel

MERCURY Quickstor Fuel Stabilizer

This Mercury fuel stabilizer is a great one if you are thinking of long-time storage of your boat engine.

Adding this Quickstor stabilizer to the fuel we can remain calm for a period of time before starting another season. The 12-ounce bottle will treat up to 60 gallons against all grades of gas and ethanol blends until one year.MERCURY Quickstor Fuel Stabilizer


  • It stops the normal and ethanol-blended fuel so that the fuel can not break down and oxidize.
  • Keeps the fuel system corrosion free
  • Defends gum and varnish from appearing in the fuel
  • Keep the fuel lines, tanks, carburetors, and injectors clean
  • Lubricates the injectors and carburetors


  • The bottle is a small one.

Yamaha ACC-FSTAB-PL-32

This product stabilizes and conditions your boat’s fuel system, preventing rust, corrosion, and ethanol damage. It is alcohol-free to prevent the buildup of gunk and varnish and it stops fuel separation prolonging the life of your fuel. It is decently priced and is good at what it does.Yamaha Fuel Stabilizer & Conditioner

However, it won’t clean the gunk that has already accumulated in your fuel system, and it doesn’t have the water fighting capabilities of some of the other products on our list. It is not recommended for fuel storage and works better as a per fill-up additive.


  • Prevents Rust
  • Alcohol-Free
  • Prevents Breakdown and Separation


  • Doesn’t Clean
  • Not for Storage

How To Choose The Best Boat Fuel Stabilizer

The best marine fuel stabilizer is not just the one that is a quality product, but the one that also meets your specific needs, at a fair price. Before deciding on a product for your boat fuel system ask yourself these questions:

  • Do I need a Marine Fuel Stabilizer?
  • How often do I use my boat?
  • Do I store my boat for prolonged periods of time?

Do You Need A Marine Fuel Stabilizer?

If you purchase fuel for your boat from gas stations, the answer is yes. Unless you’re purchasing fuel from an on-water refuel station, the fuel will contain ethanol.

Marinas aren’t required to have ethanol additives in their fuel because ethanol is extremely damaging to the fuel systems of boats. We should keep fuel stabilizers for boats in the boat winterization checklist.

How Often Do You Use Your Boat?

If you use your boat frequently and refuel the tank a lot you’ll want a fuel stabilizer that is fairly inexpensive, as you’ll use more of it.

As well as one that enhances running performance, so you can get the most from your fuel and do the least damage to your boat motor.

Do I Store My Boat For Prolonged Periods Of Time?

If you use your boat only a few months out of the year, you’ll want a product that can be used to maintain the integrity of fuel over time.

By choosing a fuel stabilizer with this feature you’ll avoid the hassle of having to drain your tank each time you plan to let your boat sit for more than a few weeks.

Fuel with added ethanol starts to break down in a very short time, after 90 days it will burn poorly and your boat won’t run well.

Select The Fuel Stabilizer Or Additive That Meets Your Particular Needs

If you want to enhance your engine performance and try to do that with a fuel stabilizer for storage, that may not work as your expectation. There are some versatile products also for our use, but, some are specially made for a particular function.

The period of time that a fuel stabilizer works properly can be an important point to check when we need a stabilizer. We must keep in mind our particular requirements before choosing an adequate fuel stabilizer.

Calculate The Quantity Of Boat Fuel Stabilizer You Will Need

Try to calculate the quantity of stabilizer you will need for your particular use and this is how we can select the right size of the container of different stabilizers. Remember, some stabilizers don’t work after a certain period of time.

Frequently Asked Questions

What is Fuel Stabilizer And Why Do I Need It?

A fuel stabilizer is a fuel additive designed to maintain the integrity of fuel. Fuel is a volatile substance and it begins evaporating as soon as it enters your tank.

In ethanol-based fuel, separation is included in this breakdown. In some engines like those found in cars this breakdown causes minimal effects, but in boats, it can cause damage fairly quickly.

As the fuel breaks down, evaporates, and separates the ethanol leaves behind a varnish-like residue that can clog fuel lines and creates a vapor that can cause rust and corrosion.

This molecule meltdown can even cause irreversible damage to fiberglass tanks, fuel lines, fuel filters, and the motor itself.

Can A Fuel Stabilizer Make Bad Fuel Good Again?

Some fuel stabilizers can improve the integrity of untreated fuel nearing its 90-day mark. However, no fuel stabilizer can return aging fuel to its original quality. In addition, adding a fuel stabilizer to old fuel won’t help it at all.

How Can I Be Sure That A Fuel Stabilizer Is Not Just normal Oil?

To be sure that you’re always getting a quality product, that does what it says it will do, be leery of huge claims.

If a product claims something that sounds too good to be true, it probably is. For example, while some items boost fuel efficiency, don’t trust a brand that claims it will allow you to get 30% more fuel efficiency per gallon.

Some products are concentrated and require less product per gallon of gas for effective treatment. But, don’t trust a product that claims to treat a full tank of gas with one drop.

If you avoid the outrageous claims, you’ll get a better product, from a more reputable brand.

Can I mix Different Fuel Stabilizers For Boats?

If you have the rest of the fuel stabilizer in your tank and want to add some more stabilizer, we recommend not to mix the fuel stabilizers if they are different.

For example, Yamaha fuel stabilizer should not be mixed with another fuel stabilizer from Mercury. They can be different in functions also.


A fuel stabilizer for boats is not just for saving our consumption of fuel but it keeps our fuel systems and engines clean and in perfect condition, It increases the lifetime of our engine.

A fuel stabilizer is also for protecting the fuel system and the engine from damage. It can be a small product but the importance is simply bigger than we often imagine. Maintaining the engine and the fuel system clean we can have better combustion of the engine. This can reduce fire hazards on board and will help us to think about searching a better place for fire extinguishers on the boat.

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