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Can You Mix Different Color Antifreeze? (Explained)

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Last Updated on: 7th September 2023, 12:38 am

Antifreeze, commonly referred to as coolant when mixed with water, is a fluid composed of ethylene glycol and other additives that regulates the engines temperature.

You should only use the type of antifreeze recommended for your vehicle. You should avoid mixing different colors together since they may contain different chemicals which can cause a chemical reaction and potentially damage the engine.

In this article, we’ll discuss whether or not you can mix different colors of coolant and antifreeze together.

mechanic pouring green coolant into a car

Why Are There Different Colors of Coolant?

Antifreeze is available in an array of distinct colors, attributed to the diverse types of coolant used by various manufacturers. The coloration of the antifreeze serves as an indicator of its coolant type and the specific vehicle it is designed for.

Does the Color of Antifreeze Matter?

The color of the antifreeze you use does matter. Various coolants are specially developed to function with certain types of engines and vehicles.

Using the incorrect coolant could potentially harm your engine. Ensuring you use the correct antifreeze for your vehicle is crucial.

Different Coolant Colors

Below is a table with the colors of coolant and antifreeze, their vehicle applications and the type of additives and corrosion inhibitors they use.

TypeCorrosion InhibitorVehicle ApplicationCoolant Color
​IAT (Inorganic Additive Technology)SilicatesOlder VehiclesGreen
OAT (Organic Acid Technology)Organic AcidsGM, Saab, VWOrange / Red
HOAT (Hybrid OAT)Silicates & Organic AcidsFord, Chrysler & other European vehiclesYellow
HOAT (Hybrid OAT, Phosphate-free)NAP FreeBMW, Volvo, Tesla, Mini, othersTurquoise
Si-OAT (Silicated HOAT)Silicates & Organic Acids​Mercedes-Benz, Audi, VW, Porsche, othersPurple
P-HOAT (Phosphated HOAT)Phosphates & Organic AcidsToyota, Nissan, Honda, Hyundai, KIA & other Asian vehiclesPink / Blue

Can You Mix Different Coolants?

It’s not recommended to mix different antifreeze colors because it could cause damage to the engine.

Different coolant colours are formulated to work with specific types of engines and vehicles, mixing them can lead to chemical reactions that can cause damage.

Can You Mix Same Colors?

It’s generally safe to mix same color coolants, but it’s always best to check the owner’s manual or consult with a mechanic to make sure it is safe to do so.

What Happens if You Mix Two Different Colors?

Mixing two different colors of antifreeze can damage your engine. Different colors contain various types of additives, using these in an engine not designed for those additives can cause issues.


It’s important to understand the different types of antifreeze and whether or not you can mix the different colors.

Different types of coolant are formulated to work with specific types of engines and vehicles, and using the wrong type can cause engine damage and overheating.

Always use the correct color antifreeze to ensure the proper functioning of your vehicle and to avoid costly repairs.

  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer. He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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