The Best Marine Antifreezes for 2023

As its name implies, antifreeze is a compound to allow a vehicle to adapt or prepare for cold weather. Winterize is the name of this process, and using marine antifreeze for engines, particularly for boats, prevents damage from the cold for these water vessels.

It’s easy to grab a container of boat engine antifreeze and call it a day. But, some of these products work better than others. If you want value for your money, and to significantly reduce cold damage to your boat’s engine, it should be in your best interest to use the best marine antifreeze.

I reviewed some of the best boat antifreeze on the market. Continue reading to know which of these products are best suited for your specific needs.

Best Marine Antifreeze Reviews

1. SPLASH 619526 Marine Antifreeze

Applying this RV and marine antifreeze to my vehicle’s engine gave me peace of mind. It provides extra durability to my motor in more ways than one.

First of all, it has a burst temperature rating of -50 degrees Fahrenheit. But, that’s not all as it also has a flash point of -225 degrees Fahrenheit. Therefore, unless there’s going to be another ice age, I know that my marine vehicle’s engines will still function with peak efficiency during winter.

Enhancing its layer of protection is an anti-corrosion feature of metal parts. In contrast, some low-quality antifreeze may put engines at risk of corrosion because of their poor formulations. Thankfully, that’s not the case with this SPLASH antifreeze.

As with other reliable antifreeze, this product doesn’t need to be diluted with water before use. This trait removes the guesswork of mixing the solution with water, which would otherwise open doors to errors if done by untrained hands.

This chemical solution also comes with a bright pink color. The bright tone helps me detect early warning signs of leakage. Some users should be warned as this pink color might look attractive to children. This concern can be mitigated by storing the product in a dark and secure place after each use.

2. Star Brite 31400R-6 Antifreeze

I thought that one bottle of antifreeze is sufficient. That was until I chanced upon this marvel by Star Brite.

This package comes in six containers of the brand’s anti-freezing solution. If all the contents are combined, they equate to 6 gallon’s worth of the solution. With this amount, I don’t have to worry about running out of antifreeze throughout winter. I may not be able to completely deplete this stock soon, which means I can give them to other boat owners in the community.

Furthermore, this non-toxic antifreeze also provides a superb solution to protecting different objects from boat engines to drinking water systems. Also, each container is meant to be used as it is, which means I no longer have to worry about guessing the correct amount of water to add to the solution.

Additionally, this compound has burst protection of up to -50 degrees Fahrenheit. Plus, it has anti-freeze protection within a range of +12 to +16 degrees Fahrenheit. This means that this solution can protect against cold damage beyond the -50-degree Fahrenheit mark.

3. RecPro RP-19937 RV Antifreeze

Excellent versatility comes in four one-gallon containers of antifreeze. This product has a solution that’s safe for use on different materials. I tested it on brass, copper, plastic, and steel, and all materials stayed perfectly fine after applying this anti-freezing compound.

Its compatibility is top-notch as I tested it on locations other than my boat’s engine and RV’s plumbing system. I also tried it on pools with more-than-satisfactory results.

Adding to its list of protective features is an anti-corrosion trait. Therefore, I can rest easy, knowing that my engine won’t be subjected to early corroding.

Additionally, this solution can serve as a lubricant to seals and gaskets. Lubrication can deteriorate during cold weather. Furthermore, without proper lubrication, engine seals and fuel gaskets are more prone to wear and tear. With this RecPro antifreeze, I won’t have to worry about these issues.

I have to say that this pack of four antifreeze containers is slightly more expensive than buying single container variants. But, the value acquired from using this solution outweighs its costs. However, the containers are fairly large, which can promote some storage concerns.

4. Sanco Industries Antifreeze Solution

Food-grade products are quite rare in the antifreeze industry. Yet, here’s an anti-freezing product from Sanco Industries that can do more than protect boat engines from cold damage.

At its core, this product is a credible antifreeze. But, the manufacturer made this product with 99.7% propylene glycol, which makes it safe to use for different applications.

For instance, a little research taught me how to combine two parts propylene glycol with one part ethanol. The result is a homemade hand sanitizer that can help kill germs, making it a quick and ideal solution during the pandemic. It’s also possible to mix this product with e-liquids for vapes.

Aside from using this product for vaping and hand sanitizing, it’s still a reliable anti-freezing agent. It effectively lowers the freezing point of water although I didn’t find information about its burst rating. So, I had to test this particular trait myself.

Thankfully, it was winter in my area and it was about -5 degrees, so I had the ideal conditions for this experiment. I poured the antifreeze into my pond and it gave me satisfying results. The water continued to flow despite the freezing temperature.

Another excellent feature of this food-grade antifreeze is its odor. Unlike other options on the market, this product doesn’t give my nose discomfort during use. Still, it does smell a bit like curry, which I find appealing. However, that might not be the case for some users.

5. Mercury Marine 877770K Antifreeze

Certain low-quality antifreeze on the market can cause gelling or an oil sludge buildup in engines. But, that won’t happen with this MerCruiser antifreeze from Mercury Marine.

For the record, gelling happens when a vehicle’s motor oil breaks down. This will, in turn, cause the excess liquid to collect on the engine, causing issues like improper lubrication. This will then lead to risks of further concerns, such as engine malfunctions and breakdowns.

From the time spent using this antifreeze, these issues didn’t surface as per my experience. Thus, I think I can safely assume that using this product can extend the life of my boat’s engine.

As an anti-freezing agent, this compound can effectively prevent water from freezing up to -34 degrees Fahrenheit. Although that figure is already good for many cases, it also means it’s not up to par with other competing products that can prevent freezing up to -50 degrees Fahrenheit. On the plus side, the brand provides a warranty for closed cooling systems from the Mercury MerCruiser gasoline engine line.

6. Ford VC-7-B Antifreeze Coolant

I bought this antifreeze last year, and it provided my marine vessel with an excellent anti-freezing guard throughout those 12 months. This product’s container even has some left of the content left after using it on my boat’s engine.

But, before proceeding, I should mention that this product is solely for Ford products only. Furthermore, it’s only compatible with diesel and gasoline engines. Therefore, this anti-freezing compound’s compatibility takes a hit.

However, when used in a Ford engine, this concentrated antifreeze solution has a performance that’s a wonder to behold. It also has a bittering agent, which is required to be added in antifreeze products in seventeen US states. In other words, this product follows certain government regulations.

Since this antifreeze is only compatible with Ford engines, I tested it on a friend’s Ford automobile. His 2003 Ford Taurus ran smoothly for thousands of miles without encountering freezing issues.

Aside from protecting engines against freezing, this antifreeze-slash-coolant can also safeguard motors from other issues, such as boils and corrosions. It also prevents intense heat buildup inside engines.

7. SPLASH 900956D Marine Antifreeze

Ending this list with a large bang is this 55-gallon giant from SPLASH. With it, I can winterize large vehicles, boats, and Olympic-sized swimming pools, or all of them without needing to purchase another antifreeze.

Kindly note that a standard boat engine needs about 5 gallons of antifreeze. Plus, the watercraft may need more than that amount for other systems like the plumbing. So, with 55 gallons, I can pour antifreeze about 11 times on my boat’s engine for an entire year.

However, 55 gallons worth of antifreeze might not be ideal for casual use. On the other hand, if anyone wants to have some of this product for their engines, I would not mind giving some of this anti-freezing compound to them. Also, I should still have more than enough left even after giving some antifreeze away.

But, its amount isn’t this product’s only highlight. It’s a non-toxic antifreeze made with a biodegradable plant-derived additive. This means that using it won’t harm nearby humans and wildlife.

Thanks to its special formulation, this antifreeze has a -50-degree Fahrenheit burst rating. It’s comparable to many competing products, but that rating should already be sufficient to prevent engines and other systems from freezing and cold damage.

8. Camco 30757 Marine Antifreeze

Starting this list with a great entrance is this antifreeze propylene glycol product from Camco. At first glance, I thought it looked nothing out of the ordinary. But, upon closer inspection, this anti-freezing solution for boats is also a great antifreeze for RVs.

However, my curiosity didn’t stop there as I tested this antifreeze in an outside water tank. This particular container had residual water at the bottom, which spelled danger as the winter months were approaching. Applying this solution to that lingering moisture prevented it from freezing, which would otherwise be a prime location for accidents.

I should also mention that this product has a more expensive price point than others. On the good side, it comes in a pack of six one-gallon jugs. Therefore, the price per gallon is lower than most competing products on the market.

This antifreeze also has a -50 degrees Fahrenheit rating. With this burst rating, it should be sufficient to protect against cold damage to my boat’s engine for the winter. It even offers extra corrosion resistance during winter.

Also, since this solution is made out of propylene glycol, it’s safe to use and dispose of without harming the environment. Furthermore, it’s a great gift to give to others in the RV and boating communities, considering I may not use all six jugs soon.

9. PEAK PER0A3 Marine Antifreeze

Buying this antifreeze has been one of the best choices I’ve made for winter for different reasons.

First, it has a burst-proof protection rating of -50 degrees Fahrenheit. I tested it by putting the solution inside a refrigerator, and I can happily report that it didn’t freeze. Further testing also proved that this antifreeze is safe for use for different materials, including brass, copper, plastic, and metal.

It’s also a breath of fresh air to see the Food and Drug Administration’s (FDA’s) seal of approval. Hence, this solution is recognized as safe for use for humans and the environment. In fact, this marine antifreeze is even safe to winterize all potable plumbing systems.

I should also mention that this antifreeze’s red color is not a mere stylish choice. Instead, the bright tone allows me to see if there’s a leak in my boat’s engine. Noticing this issue would otherwise be difficult if I were to use water for this job.

Also, there’s no mixing required before pouring the contents into the engine. I can use it full-strength without the need to dilute it first. Thus, this product saves me time and effort for winterization operations.

10. Camco 30611 Antifreeze Concentrate

From the beginning, I knew this antifreeze was going to be a cost-effective and rewarding solution to protecting my boat’s equipment from cold damage. It’s because the package doesn’t come with one container but two 36 oz. of the concentrated solution. I don’t have to pull the extra muscle to carry these containers to and from my vehicle.

Also, don’t be surprised if the container is only partially filled with the liquid. The manufacturer is kind enough to supply its customers with the correct consistency for the antifreeze for it to work properly. Hence, I only need to add water before I put it into the engine.

Still, it does mean that I need to spend a few moments mixing water with the antifreeze concentrate before using it. However, this slight drawback doesn’t get in the way of its excellent performance.

This concentrated antifreeze is also quite adaptable, seeing that I can use it on relatively any other vehicle besides boats. I have no problem using it to protect an RV’s engine. But, I should mention that this product should not be mixed with other coolant systems, nor should it be used on other vehicles if it’s not recommended by their engine manufacturers.

What to Look for When Buying Marine Antifreeze

Shopping for the best boat antifreeze can be a grueling task if you don’t know where to start looking. If you have doubts about your decisions, it’s best to take a step back and think about some essential factors before proceeding with your shopping.

So, here are five things to consider when buying winterization antifreeze for boat engines:

Propylene Glycol vs Ethylene Glycol

Generally, you can find two major types of marine engine antifreeze on the market: propylene glycol and ethylene glycol. The main difference between these two chemical compounds is their toxicity levels.

Ethylene glycol is a suitable choice for many automobile engines. But, this variant has high toxicity, which isn’t suitable for average use. Albeit antifreeze solutions with ethylene glycol as the main ingredient can still be used on boat engines, they should be handled with extreme caution. Long-term exposure to ethylene glycol may lead to harmful effects.

On the other hand, propylene glycol is a safer choice. Keep in mind that this non-toxic antifreeze tends to be the more expensive option. But, you would not have to worry about harming your health or the environment.

Antifreeze Requirements

It’s safe to say that many boat owners would use antifreeze for the winterization of their watercraft’s engines, air conditioners, and water and sanitation systems.

Choose antifreeze with temperature ratings of -50, -60, or -100 degrees Fahrenheit for engine and water systems. You may also use an antifreeze and coolant solution to provide boat systems with extra protection against corrosion at high operating temperatures.

Amount

Generally, boats would only need antifreeze once or twice per year. But, the amount needed for each application can depend on the total mileage you will travel with your watercraft.

Perhaps you have been planning a winter water excursion trip for the weekend. If so, you may need to apply more antifreeze than usual.

Consider your specific needs when choosing the right antifreeze product. Still, think about getting a large container to obtain great value. So, if you didn’t deplete the container in one application, you should still have enough for other uses. However, make sure that you check the product’s expiration date first.

Compatibility

Most boat engine antifreeze will be compatible with relatively all engine types. But, some unique formulas that exist on the market are best suited for certain marine engines.

Don’t forget to check your boat owner’s manual to see what type of antifreeze is best suited for your watercraft’s engine. Usually, antifreeze is compatible with 2-stroke engines. But, you can also buy a universal antifreeze if you don’t want to do much thinking on this matter.

Price

Most antifreeze on the market shouldn’t break banks. But, you still need to consider your budget before making your ultimate decision. After all, you do not want to go over your spending allowance to buy antifreeze. Otherwise, you might have difficulties purchasing other essential items for your boat.

Make sure to follow the manufacturer’s instructions, especially the dilution ratio, regardless of the antifreeze you choose. Kindly note that you’re mostly paying for the formulation, which can have a range of 25 to 95% ethylene or propylene glycol. Hence, products with lower temperature ratings tend to be more expensive. Shop smart, and always keep in mind that a less expensive option does not always offer the best value.

Frequently Asked Questions

What are the Most Trusted Marine Antifreeze Brands?

It’s possible to find many trusted marine antifreeze brands. Some companies, like Mercruiser, RecPro, and West Marine antifreeze provide boat engine winterization solutions that outclass many of their competitors.

Aside from those companies, Camco is another business in the marine antifreeze sector that also shares some of the limelight. Started in 1966, this company prides itself on selling antifreeze as it’s the first product in the business’ wares. As the years went by, Camco spread from Greensboro, North Carolina to local and international locations.

Another company worthy of mentioning is PEAK. This business has a 40-year history in developing quality products. Motor oils, windshield wipers, antifreeze, and coolants line the business’ shelves for its customers.

Next, there’s SPLASH, which has catered to different antifreeze needs since 1995. Factory Motor Parts (FMP) bought a small St. Paul factory called Fox Packaging which produced windshield washer fluid. Soon, Fox’s product changed to the SPLASH brand that many now know and love.

Last, but not least, is Star Brite. As for this brand, it started by selling auto polish instead of antifreeze at the beginning of its operations in 1973. The company’s success leads to the development of boat maintenance products.

What Kind of Antifreeze do I use to Winterize my Boat?

The market sells two main types of antifreeze, which are ethylene and propylene glycol. So, which one should you use on your boat?

Both can help prevent cold damage to your watercraft’s components. However, one is more toxic than the other.

Ethylene glycol, in particular, is quite poisonous to the environment. Frequent exposure to this chemical compound can bring harm to animals and humans. Further, ethylene glycol marine antifreeze is generally more difficult to dispose of correctly.

Propylene glycol marine antifreeze, on the other hand, is a safer option. This chemical is generally biodegradable, odorless, tasteless, and, best of all, non-toxic. It’s for these reasons that propylene glycol is the better option to winterize your boat.

Should I Drain Antifreeze After Winterizing Boat?

The answer to that question is, “It depends on your boat engine.” Thus, it’s a critical step to check your owner’s manual first to identify the type of engine your boat possesses.

Here’s a quick overview of each type of boat engine and whether you should drain antifreeze on them after winterization.

• Inboards

Inboard boat engines generally use water drawn from the outside to keep their motors cool. Winterizing inboards involves the use of year-round coolants with sufficient mixtures to meet engine manufacturers’ recommendations.

If you don’t use your boat’s inboard motor often, you may have leftover antifreeze in the engine. If so, drain it first before replacing the solution with a fresh mixture. Moreover, this need bears more importance if the engine has signs of dirt or rust.

• Sterndrives

Many sterndrives aren’t selective about their winterization procedures. In other words, it’s optional to drain the engine of antifreeze before re-winterizing your boat.

• Outboards

Modern outboard engines now exist on the market with automatic winterization features. So, if you manually winterize these motors with manual methods, you might bring more harm than good to them. But, if your boat’s outboard motor requires manual winterizing, completely drain it before applying fresh antifreeze.

Can You Use Marine Antifreeze in a Car?

Some boat owners might wonder about the difference between marine antifreeze vs. auto antifreeze, and you may be one of those individuals. Particularly, you’re thinking if you can use antifreeze for boat engines on cars.

Although both products act similarly, they’re made with different substances. Most auto antifreeze generally has ethylene glycol as the main ingredient. With this chemical compound, it makes auto antifreeze more potent than marine antifreeze.

With that in mind, it’s not a good idea to use auto antifreeze on marine watercraft. Further, the same can be said for the opposite. In other words, don’t use marine antifreeze in a car.

How to Care and Maintain?

RV & marine antifreeze products are usually easy to maintain. But, one wrong step can ruin the formulation and bring potential harm to your vehicle’s engine. So, here are some quick tips to help you care for and maintain your antifreeze for boats.

• Don’t transfer the product to another container. Keep the solution in its original packaging. Trustworthy brands already take their products’ containers into account. Transferring the antifreeze may increase the risks of contamination.
• Store in a dark place. Save your investment by keeping it in a cupboard, garage, or shed. Also, make sure that the lid is tightly shut. Furthermore, ensure that the child safety lock is functioning properly.
• Use a funnel to prevent leaks while pouring.
• Don’t remove the product’s safety information.

Where to Buy?

You can relatively buy marine antifreeze in different stores, thanks in part to technology. But, consider not clicking the “Checkout” button on a random online antifreeze retailer. Avoid regret by shopping the smart way.

If you plan on buying online, make sure you’re buying from a credible source. Some retailers, like Home Depot and Amazon, list products that come from noteworthy brands. Furthermore, these online providers heavily scrutinize the products that go into their list of offerings. Hence, you can have peace of mind, knowing that the product you will get is the one that you ordered.

Otherwise, buying from a non-credible source can increase the risk of you getting scammed. Think about it – you don’t want to buy antifreeze and receive a container of water, do you?

The same ideology is true when buying marine antifreeze from physical establishments. Ensure that you’re buying from a trustworthy store that roughly follows industry-standard price ranges. Therefore, make sure to research your preferred antifreeze first to know its standard retail price to avoid paying more cash than intended.

How to Properly Dispose of Antifreeze?

At its core, antifreeze is a chemical compound, and improper disposal can bring harm to Mother Nature. Therefore, it’s best to learn about how to dispose of the solution to protect yourself and the environment.

Still, disposal can be quite easy if you’re using biodegradable antifreeze. If so, you can safely dispose of it by pouring it down relatively any sewer system. But, don’t drain it onto your garden or you’re going to kill the plants.

When in doubt, consider contacting your local hazardous waste removal company. They can properly and safely get rid of the antifreeze for you.

Conclusion

Upon reaching the end of this buying guide, you should now have a better idea of the best marine antifreeze to buy. Don’t forget to consider certain factors, like the main ingredient, intended application, and price, before finalizing your decision.

Still, if you want to proceed with my suggestion, I recommend the Camco 30757 antifreeze. You can’t go wrong with this product, especially after seeing its top-notch features and characteristics in action.

Dave L. Beaton

I am Dave, Marine Talk’s content creator. Boating experiences matter when planning a boat trip for your family or going by yourself. Therefore, I am here to tackle all things relevant to boating so even the inexperienced ones can start their boating safely.