Antifreeze And Coolant For Your Car – How To Choose And Why Do You Need It?

By Mark Hawks, Page Garage

Owning a car gives us the freedom to travel long distances regardless of the weather conditions outside. In cold weather, our vehicle keeps us warm by heating the interior, and in hot weather, it keeps us cool, thanks to the air conditioner.

But have you ever thought about how the vehicle engine functions seamlessly even with outside severe temperature changes?

Credit: Sergey Tikhonov, RU

Antifreeze is one of the most necessary ingredients for all vehicles. It is a concentrated, glycol-based liquid that must be diluted with water before use. Coolant is a mixture of antifreeze and water, generally with a ratio of 50:50, and is the fluid that needs to be maintained in the radiator. With the help of antifreeze, coolant helps maintain the engine’s temperature at a specific level depending on weather, vehicle, and engine model. The mixture also helps the engine from rusting and other technical problems.

Coolant mixtures should use the antifreeze specified for your engine model and must be checked and changed by the mechanic regularly. Generally, when a vehicle is serviced, the coolant is checked and replaced.

If the coolant is not replaced frequently or does not wear out naturally by the engine’s functioning, there can be irreversible damage. If the coolant is not correct, moisture will likely form in the engine, which will corrode it and unnecessarily heat the engine giving rise to vapors. Thus, the entire vehicle could come to a standstill when this happens.

Other minor problems caused by ignoring coolants are:

  • Air Conditioning
  • Heater
  • The flexibility of other vehicle components such as the clutch, brakes, etc.

Automobile industries continuously define new norms and products and now there are coolant products that do not require the mixing of water. A variety of products vary, depending on the needs of the engine and the advice of professionals. The best practice is to ensure that you have the correct mixture per your engine requirements.

How to Choose the Right Product?

Antifreeze come in many different colors. The green one is the most common, but that does not mean it can be used for every vehicle.

Pouring the wrong liquid in your vehicle can be wrong for many reasons. To learn more, read here about the different coolants and antifreeze liquids, which you should use according to your vehicle and engine type.

There are also different coolant mixtures specified for European, Asian, and American vehicles. And also for newer and older vehicles.

Below, check out the different mixtures which correspond to brands.


The IAT (Inorganic Additive Technology) is the most common and the oldest antifreeze used in vehicles to date. It is the green-colored one, which has silicates—the base technology for coolant mixtures.

The best thing about IAT is that it is known to protect engines from corrosion for many decades. Mechanics prefer this mixture for older vehicles as this is a proven formula.


The OAT (Organic Acid Technology) is an advanced version of antifreeze. It is orange in color and has organic acid as the base technology. These are known as long-life coolants as they are known to keep the engines in good health for a long time.

While keeping the temperature stable, it is also the best anti-corrosion liquid. Vehicle models from General Motors, Volkswagen, Saab, etc., rely on OAT mixtures for the working of their engines. This antifreeze is vastly used as it exceeds the engines’ performance and keeps it running for a more extended period.


The HOAT (Hybrid Organic Acid Technology) antifreeze has silicates and organic acids as the base technology. These are generally yellow and are used in Ford and many European vehicles.

As the name suggests, HOAT is a derivation of OAT, innovation in OAT antifreeze. This hybrid mixture is widely used in Europe for European-standard vehicles.


The phosphate HOAT is another antifreeze that was derived from OAT and HOAT. It is based on phosphates and organic acids. The turquoise color makes it look cool, and Tesla vehicles widely depend on it. Vehicles from BMW, Mini, Volvo also use P-HOAT and trust its technology.

These types of vehicle engines need to give great performance, so they need something extra. Moreover, P-HOAT has exceeded multiple industry specifications and is trusted widely.


The Silicate OAT is one of the most expensive and customized antifreeze made for superior power engines. Brands like Mercedes, Audi, Porsche have been recommending the SI-OAT for their vehicles.

The SI-OAT mixture is known to maintain the engine in the best way possible. The silicates work well to prevent the engine from corrosion.

Credit: bandita

To find out the best antifreeze for your vehicle, it’s always best to consult the vehicle owner’s manual or dealer and mechanic to ensure you are using the best coolant.

Final Thoughts

Antifreeze and coolants play a significant role in the functioning of your vehicle. So, if you love your vehicle and want it to run seamlessly, you need to take good care of it. Choosing and maintaining the right coolant fluid in your engine is the basis of taking good care of your vehicle.

Educate yourself about the fluids used in your vehicle from your vehicle-dealer, mechanic, and whomever you consult for the maintenance of your vehicle.

Next time you enjoy driving your vehicle, be it hot or cold outside, don’t forget to say ‘thank you’ to the coolant for keeping the vehicle healthy and comfortable for your drive!

Mark Hawks is a skilled car mechanic and experienced technical consultant working with many automotive resources. He is a big fan of car tuning and even took part in serious motorsport events. Currently, he is working as a technical writer and consultant for car goods review at the Page Garage.

Editor’s Note: The opinions expressed in this article are those of the author.

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