The 7 Best Antifreeze Testers Out there! Buyer’s Guide (June 2021)

best antifreeze testers

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If you have a car or two, you should get acquainted with some car components which need regular attention. One of them is the antifreeze coolant solution which is poured into your radiator.

This solution stabilizes the heat or coolness inside the radiator which is important for the efficient operation of your engine. One important instrument which helps you determine if the antifreeze coolant is still working for your car is a device called an antifreeze tester, sometimes called a coolant tester and also at times, an antifreeze hydrometer.

It is a device which should accurately determine if the solution inside your radiator is mixed properly with water or is already losing its effectiveness in maintaining proper radiator temperature which doesn’t freeze out or boil over.

You should get acquainted with various testers in the market in order to know what is best for your needs and your type of automobile.

In a hurry? Check out our top 3 picks that we highly recommend!

Preview ImageProduct NameQuick Links to Amazon
Hobein Antifreeze Refractometer Check Price On Amazon
Prestone AF-1420-6PKCheck Price On Amazon
ATD Tools 1106 ProfessionalCheck Price On Amazon

The Best Antifreeze Testers

Hobein Antifreeze Refractometer

It displays only in Fahrenheit the checking of the freezing point of automobile antifreeze coolants.

But it multitasks and doubles as a Battery Acid tester too which gives you a quick opinion about the battery charge condition.

Unlike other antifreeze coolant testers which need substantial coolant liquid to suck out and test, this device only needs 2 to 3 drops of solution, and after a few seconds, you get an accurate reading.

The correctness of reading is also because of its automatic temperature compensation (ATC) feature.

It is easy and durable to carry around because its majority material is chromium, which is a light but sturdy material.

Sealey Ethylene Glycol Antifreeze Tester Twin Rotor

It has a feature compensation rotor that adjusts immediately after the reading whatever the coolant temperature is. The freeze protection level is only read in degrees Celsius.

Any kind of coolant can be tested by the Sealey branded tester as long as it is an ethylene glycol antifreeze mixture.

Buyers of their tester say that aside from being inexpensive, it is simple to use. It costs only one fourth of other tester brands, but it does the job of testing antifreeze coolants, whether hot or cold, just as well and efficiently.

Overall, it’s a quality United Kingdom manufactured engine instrument. It is a tool which would be useful for both mechanics and for DIY enthusiasts.

Atd Tools 1106 Professional Antifreeze and Coolant Tester

Several thousands of customers are satisfied with this product, given its affordability and its simplicity. It easily checks the functionality of the antifreeze and coolant.

It is also compatible with any ethylene glycol coolants, which includes GM Dec-Cool. It’s a disc type tester which is quite accurate and reads at both Celsius and Fahrenheit. What’s more, it has a small turdy, shatter resistant, transparent housing that could hold through countless uses.

Although thousands are satisfied with the ATD Tools 1106 Professional Antifreeze and Coolant Tester, there are some complaints that they have just used it for 3 to 6 months and the rubber boot is already broken. And the warranty is not clear on the package.

It is also a reliable tester for antifreeze and coolant checking of marine crafts, various variants of motorcycles (from small to large, to urban and sporting bikes), utility vehicles, all terrain vehicles and snowmobiles.

Many customers say that despite its low price, after they have used it for a few months, they would not ask for a replacement anymore. It has already paid its dues after a couple of months of use, even if it breaks down.

Abn Deluxe Antifreeze and Coolant Tester Hydrometer Tester – Automotive Antifreeze Tester for Ethylene Glycol Coolant

On the product itself, it says Rapid Test. Because in just relatively a few minutes, you can already determine if the antifreeze coolant is still of good quality or needs to be flushed out.

Before your antifreeze coolant freezes up in winter or boils over in summer, you will have known well in advance if you regularly use this ABN branded deluxe tester which has a clear capsule.

Aside from being a reliable antifreeze coolant tester because of its sensitive pointers, it can be used as a tester for the freezing point of your windshield water reservoir.

The pointers are convenient for the user compared to standard coolant test strips because there is no need to concentrate on the color or PH balance to determine the freeze and boiling points of your solution.

On one side is the freeze point scale and on the other side is the boiling point scale. It reads in both Fahrenheit and Celsius and is compatible with all ethylene glycol coolants.

Its clear capsule allows you too to do a visual inspection of the antifreeze for dirt, rust and other sediments which might have infiltrated it.
There are customers with multiple cars (Chevy, Dodge, Honda, etc.) who inquire if the ABN Deluxe tester can tackle several car brands. It definitely can be used as an antifreeze coolant tester on different car brands.

With regards to sucking out the sample coolant, this tester makes it easy for you because of its large rubber bulb and 5.5 inch long rubber tube which facilitates convenient sucking of the liquid into its plastic reservoir.

It has easy to read instructions on the stickers unlike other testers which don’t have any instructions at all.

Prestone AF-1420-6pk Antifreeze Coolant Tester

It is probably one of the most low cost antifreeze coolant testers in the market but many customers have commented that they are still using it after a few years.

The procedure and the expectations for this device are conventional and it fulfills what is expected of it. You suck out through its rubber hose a sample quantity of coolant to read its temperature and in order to visually inspect if there are foreign sediments inside the liquid or if there is corrosion buildup.

To be able to have an accurate reading again next time, make sure to flush out the coolant sample with water.

Despite its low price, it could be used as an antifreeze coolant tester on a wide range of vehicles including marine craft, motorcycles, snowmobiles and your car of course. This is as long as the coolant being tested is ethylene glycol based.

Agriculture Solutions Antifreeze Refractometer

It reads only in Fahrenheit and has two functions.

Its first function is to measure the freezing point of either ethylene glycol or propylene glycol coolant. Its second function is to measure the specific gravity of battery acid and to check the condition of battery charge.

You will only need 2 to 3 drops of solution for testing, and in seconds you get a result. What’s more, it also has an Automatic Temperature Compensation (ATC) feature which diminishes the influence of temperature on accuracy.

It is portable and accurate, and you need no battery. Your purchase includes a hard case with droppers, screwdriver, user manual and cleaning cloth.

Amtast Digital Coolant Refractometer

This might be one of the more expensive antifreeze coolant testers in the market. But if it fits your needs, why not?

It’s unlike other testers which only tests ethylene glycol based coolants because it can also test propylene glycol based coolants.

It is also a multi-tasking tester. It could also test the condition of your battery fluid and your screen wash antifreeze and also check the concentration of urea in Adblue.

It’s not like other testers which require substantial coolant quantity for testing. You only need a few drops of solution and in seconds, you get an accurate reading. Accuracy is enhanced by the Automatic Temperature Compensation Feature (ATC) which is important for a refractometer.

You will also like its low power consumption feature because after not being used for 1 minute, the meter will automatically power off.

Aesthetics wise, it looks exquisite, and it has portability. Many customers have been continuously using it for a long time.

Prioritize Safety When Testing Your Antifreeze Coolant

No matter what antifreeze coolant tester you will finally decide to purchase, be always alert to safety measures when checking your coolant.

Antifreeze is mixed with water in order to create an engine coolant. Regularly check this important car component because this antifreeze coolant protects your engine from freezing in the winter and from boiling over in the summer or any type of hot weather.

Always do the testing of the antifreeze or coolant when the car is off and the engine is cold.

You will only need a few seconds to a few minutes to complete this test.

It is recommended that with a tester, you check your antifreeze coolant regularly so that your car engine will maintain the right temperature all the time, in all types of weather.

Two Methods of Testing

There are two types of testers in the way they test the coolant, as you have observed in our recommended products.

One Type Is Through a Suction Hose in Which You Vacuum in Enough Coolant Into the Container, Then You Can Start the Test

The other tester type needs 2 to 3 drops of the coolant solution for testing.

For both tester types, if there is any discoloration (brownish or reddish) or there are sediments, debris, or rust floating inside the liquid, flush out the antifreeze coolant immediately and replace with a new refill. The normal color of the coolant is usually green.

And when checking the temperature with the tester, the normal temperature for freezing point is – 34°F or – 37°C and the boiling point temperature should read 265°F or 129°C. This means that the coolant is still doing its job of protecting the engine.

Coupled with the fact that there is no discoloration and no sediments floating in the coolant, everything is in order and it doesn’t need to be flushed out yet.

Automatic Temperature Compensation (Atc) Feature Is Ideal in an Antifreeze Coolant Tester

An effective tester should ideally also have Automatic Temperature Compensation or ATC. It is a measure for surmounting an undesirable factor which makes the reading inaccurate.

Some testers have ATC while some testers don’t have ATC. But having ATC on a tester will make the tester yield accurate results, and that is what really matters.

What Kind of Antifreeze Tester Should You Aim For?

The Tester Should Ideally Be a Multi Tester for Different Car Fluids and for Various Vehicle Variants and Brands

An ideal tester should also be a multitasking device. It should not be only an antifreeze coolant tester, but also a battery fluid, diesel exhaust fluid, Adblue, and windshield washer fluid tester.

It should also be compatible to work not only for testing on automobiles but also on scooters, trucks, marine craft and snowmobiles.

The length of the suction hose is also important because the coolant tank of a car is deep and it could be difficult to suck out samples of coolant which could be deep down.

But there are testers which conveniently only need a few drops of coolant for testing. And the ideal tester should be adaptive to any ethylene glycol based coolant because it is the most popular and most used kind of coolant.

Compatibility to other variants of coolants is an added plus.

Affordable and Reasonable Price

How many vehicle owners in the world are willing to pay more than $100 for one single tester, when it’s not the only vehicle expense that they have to shoulder? Not too many people.

What’s important is that a tester that’s reasonably below $50 in price does its mandated purpose to give you an accurate reading and visual analysis of what’s going on inside your radiator so you can execute the proper steps to maintain the overall fitness of your car.

Visual Clarity When Reading Results

Some testers have readings in both Celsius and Fahrenheit, and some have a reading in only one of them. But it doesn’t really matter as long as you’re familiar with how to interpret the reading.

After Every Testing, Always Flush Out With Water

And no matter what tester you buy, flush out the coolant you tested with water (after the testing) so that you’ll get an accurate reading the next time you use the tester.

Basically, what was discussed above is the procedure when testing the condition of the antifreeze coolant. There are so many testers in the market and it makes you confused on what is worth your money.

But the fact is that you need an antifreeze coolant tester of your own so that your car engine is always in tip top condition. And you have the luxury of checking the antifreeze coolant anytime, as long as the car is off and the engine has gone cold.

The worst thing that could happen is if you are impatient when the engine is still hot and you open without warning the lid of the coolant tank. The hot liquid can spray right into your face and burn your face and damage your eyes.

But no matter what tester you are going to buy, it is recommended that you flush out your antifreeze coolant if it is one year old and replace it with a new purchase. It’s not going to do its work of cooling down your engine if it gets too old.

My Personal Preference

The testers in our most range in price from $4 to $190. I’m a practical kind of guy who doesn’t want to spend much on automotive tools as long as what I’m purchasing does its job.

It doesn’t matter to me if it reads only in Celsius or Fahrenheit. I’ll get used to it.

But I do care about the feature called Automatic Temperature Compensation (ATC) which ensures accuracy for the readings by reading the influence of temperature on the correctness of the readings. Because of what use is a tester if it isn’t accurate. It will mislead you.

And I like the testers which need only a few drops of solution in order to get a reading compared to those testers which need to suck out a substantial quantity in order to perform.

With all these in mind, what’s best for me is the Hobein Antifreeze refractometer.

It only reads in Fahrenheit (I don’t care, I’ll get used to it), has the important ATC feature, needs only a few drops to get the testing going, and costs only $17 on Amazon. A price that’s so low you will be astonished that some people have it in their garage for years and it is still functioning.

It’s also being a battery acid tester is an added plus too. And it’s made of sturdy and long lasting chromium.

What’s best for you?