What is Antifreeze Used for in Cars?

What is Antifreeze Used for in Cars?If you are like most car owners, you have probably heard about antifreeze. But, do you know what antifreeze is used for in cars? You might be surprised to learn that all vehicles in every climate rely on antifreeze to keep running smoothly.

Antifreeze is used to regulate the temperature of your car's engine to protect the engine and its components from overheating or freezing during extreme temperatures. The cooling system of your car also relies on antifreeze to prevent corrosion over time.

You might be more familiar with the term coolant. The words antifreeze and coolant can be used interchangeably because they both refer to the same fluid.

Now you know that antifreeze (or coolant) is a vital fluid used in your car’s cooling system. Keep reading, to learn about the different types of antifreeze, and why it is so important to choose the right antifreeze for your car.

Is Coolant the Same as Antifreeze?

Yes! You will most commonly hear antifreeze referred to as coolant. They are both the same.

What Types of Coolant/Antifreeze Are There?

Antifreeze is sold to you as a pre-diluted liquid, and typically the base consists of water and either ethylene glycol or propylene glycol. Colors such as pink, orange, yellow, blue, or green result from the antifreeze manufacturers' use of different chemical combinations of additives and dyes.

Color might signify a purpose such as extended mileage or anti-corrosion, but, there is no industry standard for antifreeze color. It is best to read the ingredients on the bottle versus simply choosing an antifreeze by color. Always check your owner's manual for the manufacturer's recommended antifreeze. Different makes/models of cars require different types of antifreeze.

There are three (3) basic groups of antifreeze, depending on the composition of the liquid:

  1. Inorganic Additive Technology (IAT) - Its green color most often recognizes the most commonly used worldwide, IAT antifreeze. IAT antifreeze uses silicate and phosphate as excellent corrosion inhibitors. But, these chemicals have a short life span, so the antifreeze should be changed every other year or every 30,000 miles. Colors include green.
  2. Organic Acid Technology (OAT) - These types of antifreeze use organic acids like 2-ethylhexanoic acid or 2-ethylhexal acrylate as corrosion inhibitors. OAT corrosion inhibitors are slower, acting with a longer lifespan so, the antifreeze should be changed every five years or 150,000 miles. Colors include GM’s DexCool orange, Audi’s pink, and Honda’s dark green.
  3. Hybrid OAT - A hybrid mix of IAT and OAT, these types of antifreeze combine environmental friendly OAT chemicals with a small number of silicates for ultimate corrosion protection. Currently, Hybrid OAT antifreeze is labeled under several names, including G-05 (Europe), G-11 or G-12 (Audi), and Global. Colors include Volkwagen’s pink, Toyota’s red, and Mercedes-Bendz’s purple.

Automotive manufacturers often endorse brand-specific antifreeze to meet industry specifications. For example, ZEREX brand antifreeze has been automaker approved by General Motors (Ford, Chevrolet, & Mercedes-Bendz). Automaker approved antifreeze brands, such as ZEREX, tend to come at a higher cost and might not be the right choice for older car makes/models. If ZEREX has an antifreeze that is right for your vehicle, you can purchase it at a dealership, car service center, or on Amazon. ZEREX antifreeze types include Original Green (IAT), DexCool Orange OAT Formula, and G-05 Formula.

You might be more familiar with aftermarket antifreeze, such as Valvoline, Mopar, or PEAK. These brands you can find at most automotive stores and Walmart. Aftermarket antifreeze tends to be more affordable and just as functional if it is the right choice for your car. Easily purchase Valvoline’s MaxLife on Amazon or Mopar’s 10 Year/15,000 Mile Coolant on Amazon.

Remember to check the owner’s manual for your car or truck to determine which type of antifreeze is required for your specific make/model.

What Happens if You Use the Wrong Color Antifreeze?

Keeping the antifreeze topped-up in your car’s cooling system is nearly as important as keeping the right amount of oil flowing through your engine. Without antifreeze, your car can suffer insurmountable damage. But, what happens if you mix different colors of antifreeze?

Automotive experts agree that mixing different colored antifreeze is not a good idea. Because there is not an industry standard for the color of antifreeze, color is not a good indication of what type of antifreeze you are using.  Best to read the label to determine if your antifreeze is IAT, OAT, or Hybrid OAT.

Mixing different types of antifreeze can generate a chemical reaction that changes the texture of the liquid. The newly combined antifreeze might be a thicker, gel-like substance that cannot flow fluidly through the cooling system. Mixed antifreeze can cause clogs in your cooling system. Clogs potentially lead to your car’s engine overheating or problems with your car’s water pump, heater cores, radiator, water jackets, or head gasket.

Check your owner’s manual to determine exactly what type of antifreeze is recommended for your car. Do not top-up your cooling system with an unknown type of antifreeze.  If you are not sure what type of antifreeze is currently in use, flush and refill the cooling system as a whole.

Do You Need Antifreeze in Your Car?

Every car needs antifreeze to protect the engine’s components from either overheating or freezing. Antifreeze regulates the temperature in the car’s radiator. During summer months, antifreeze raises the temperature of the boiling point to prevent the overheating. During winter months, antifreeze lowers the temperature of the freezing point to prevent freezing.

Even electric vehicles (EV) rely on a cooling system that uses antifreeze. The battery cells in EVs generate heat during charging and discharging. Antifreeze running through a thermoregulation system prevents the batteries from overheating.

How Much Antifreeze Does My Car Need?


It’s a good idea to check your car’s antifreeze level occasionally. Keeping the antifreeze topped-up will prevent your car from overheating and avoid corrosion in the cooling system. Check your owner’s manual to determine how much antifreeze your car’s cooling system needs.

To check the antifreeze level, you will need to use an antifreeze hydrometer which you can affordably purchase on Amazon. Make sure the car’s engine is cool to avoid burning yourself.

Locate the antifreeze reservoir tank or overflow tank located near the radiator. Your owner’s manual can instruct you on the exact location of this transparent, plastic tank. Insert the hydrometer into the opening on the reservoir tank and suck the antifreeze into the hydrometer. Fill the hydrometer. Here are some tips on how to properly read the antifreeze hydrometer.

If you have determined that your car needs antifreeze, remember not to mix antifreeze colors. Refer to your owner’s manual to determine what type of antifreeze your car uses. Most of today’s antifreeze is pre-diluted to a 50/50 antifreeze to water ratio, ready to add to your vehicle. Check the label and if you are not sure about the antifreeze to water content, consult a mechanic.

Can You Use Water Instead of Antifreeze?

Water should not be used as a substitute for antifreeze because water cannot prevent the engine block from freezing during extreme temperatures.

Additionally, water does not protect the cooling system from corrosion, as well as modern additives do. Today's antifreeze formulas contain anti-corrosive and anti-foam additives that keep the cooling system working efficiently, diminishing the build-up of deposits.

Are Windshield Washer Fluid and Antifreeze the Same?

No! Windshield washer fluid is used to improve your visibility by washing the exterior surface of your windshield. Antifreeze (or coolant) is used in your car’s cooling system to prevent the engine’s components from overheating or freezing.

The ingredients of windshield washer fluid, primarily methanol, are meant for cleansing. Some windshield washer fluids do contain small amounts of ethanol to prevent the liquid from freezing in extreme temperatures.

If you accidentally poured windshield washer fluid into your car’s antifreeze reservoir, we recommend consulting a mechanic. Automotive experts suggest the cooling system be flushed and refilled as soon as possible to avoid damage from contamination.

Antifreeze (or coolant) keeps your car’s engine running smoothly. Help to maintain your car’s engine by choosing the right type of antifreeze and keeping your car’s cooling system topped-up.

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