5 Best Boat Engine Antifreezes (Reviews Updated 2022)

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Maintenance of a boat engine is an important part of keeping a boat running smoothly. Regular checks and services prevent the engine from seizing up or breaking, resulting in potentially expensive and time consuming repairs. Boat engine antifreeze helps to keep an engine healthy and running smoothly by preventing the oil and other parts of the engine from freezing in cold weather.

Best Boat Engine Antifreeze

Here are our Boat Engine Antifreeze reviews.

1. Non-Toxic Anti-Freeze 50F

Non Toxic Anti Freeze 50f

The Non Toxic Anti-Freeze 50F is a highly functioning anti freeze specifically for marine engine use. It is good value for money. This boat engine anti freeze comes in a 6 gallon bottle so it should last a boat owner a long time.

  • Non-toxic composition
  • Prevents freezing in the coldest of conditions
  • Easy pouring bottle
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2. AMRW-K3-50 Inboard Winterization Kit

Amrw K3 50 Inboard Winterization Kit

The AMRW-K3-50 Inboard Winterization Kit is a complete kit of antifreeze and other products designed to maintain a boat engine. Included is the antifreeze, fogging oil, and fuel stabilizer. This set is great value for money.

  • -50 degree anti freeze
  • Handles extreme cold consitions
  • Non toxic
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3. Mercury Mericruiser Quicksilver OEM Anti-Freeze

Mercury Mericruiser Quicksilver Oem Anti Freeze

The Mercury Mericrusier Quicksilver OEM Anti-Freeze is a premium quality anti freeze from a reputable marine manufacturer. This anti freeze formula is ready to use and pre mixed with deionizer water. It is under customer warranty.

  • Provides protection to -26 degrees
  • Extends engine life
  • DEX-cool compatible
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4. PEAK RV & Marine AntiFreeze

Peak Rv & Marine Antifreeze

The PEAK RV & Marine AntiFreeze is a high performance anti freeze formula. This boat engine anti freeze also doubles up as engine coolant making it a versatile choice. It is an affordable, good value option.

  • -50 degrees antifreeze
  • Low toxicity forumla
  • Made for extreme cold conditions
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5. Rexcro AntiFreeze Winter-Pruf

Rexcro Antifreeze Winter Pruf

The Rexcro AntiFreeze Winter-Pruf is a highly functioning anti freeze specifically for boat engine use. It is good value for money. This boat engine anti freeze lubricates seals and gaskets and is safe for engine blocks.

  • -50 degree burst protection
  • Doesn’t harm steel, plastic or copper plumbing
  • Non toxic compostion
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Boat Engine Antifreeze Buyer’s Guide

Choosing high quality boat engine antifreeze is a wise investment for a boat owner. A relatively low priced-item, engine antifreeze could be mistaken as not being important. In terms of maintaining the good condition of the engine, it is actually a very important item. The wear and tear of a functioning boat engine and the metals rubbing together will inevitable cause damage over time especially in cold conditions. Engine antifreeze protects and prevents this damage from happening.

Our buying guide reviews the best boat engine antifreeze on the market so you can choose the right antifreeze for your engine. Following are some common features of boat engine antifreeze to look out for when considering which one to purchase.


The viscosity of boat engine antifreeze is the measurement of how easily antifreeze functions at specific temperature. The lower the temperature which the product can function at is, the more effective the antifreeze. -50 degrees is industry standard and this will generally handle any extreme cold weathers in the harshest of winters.


Choosing boat engine antifreeze which provides a range of functions is a good idea. Some antifreezes lubricate the engine therefore prevent corrosion. Others work to protect other parts of the fueling system. A combination of functions should be top of the list when looking for the right boat engine antifreeze.


Boat engine antifreeze is the type of product which you apply periodically when the need arises. Generally, applying the antifreeze once or twice per year will be enough. This can vary depending on the amount of mileage you will travel on your boat, which may mean you require more regular application. Getting good value by checking the amount of antifreeze you will get for your money is a good idea. A good bottle of engine antifreeze should last you a long time if you purchase a significant amount.


Boat engine antifreezes are compatible with different engine types. Some will be suited to certain types of engines. Other antifreezes will be compatible specifically with 2-Stroke while others will be universal.