Can you mix orange and green antifreeze?

Antifreeze is crucial for cooling the engine. It has more properties besides cooling, an important feature lies in its name because it has the ability not to freeze at low temperatures in winter and, thereby, maintain the engine in good working parameters in the winter.

There are a lot of antifreeze types out there each having its own properties like color and composition. Each manufacturer recommends a specific type of antifreeze in the car manual that the driver must consider to avoid using the incorrect coolant type that can cause expensive damage to the car.

To add a quick answer to the question above, you should under no circumstances mix green and orange antifreeze, because they are composed of different substances and have different chemical properties. When they are mixed, those good properties will be lost and this mixing can cause a chemical reaction that can do a lot of damage to the engine.

What is antifreeze made of?

Antifreeze contains 80% of distilled water that is mixed with ethylene glycol. The remaining 20% are additives that have special characteristics to a particular coolant type.

These additives and substances are needed to neutralize the destructive effect of water and ethylene glycol on the metal parts of the cooling system, in particular cooling system pipes and the radiator.

The antifreeze protects pipes and other cooling elements from aggressive effects by forming a thin layer of film. It can also have anti-corrosion properties that are more commonly used in G12 and G12 +.

In addition, there is another type of antifreeze, like G13. They combine the chemical elements of both previous categories. Therefore, they are considered versatile and suitable for refilling. But not always!

What features does orange antifreeze have?

The orange antifreeze is a G12 type. Its composition is based on ethylene glycol, water, and additives ( borates, nitrites, etc.), but additionally, they include compounds of carboxylic acids. They have a lifespan of up to 5 years and have a wide range of use.

What features does green antifreeze have?

The green antifreeze is a G11 type. Its composition is similar to G12, but it does not include carboxylic acids. They have a lifespan of up to 2 years and are mostly used in older car models, therefore, they should be changed more often.

Moreover, there is G12 + which is a mixture of water, ethylene glycol, and additives. The components that are available in G12+ antifreeze may differ, it depends on the manufacturer and they are most often in red color.

G12 ++ is also a hybrid antifreeze. For their manufacture, an organic base and silicic acid compounds are used. In terms of properties, they are similar to the G12+, and their main difference is a longer lifespan. Available in red, and sometimes yellow colors.

G13 is a relatively new antifreeze. Its basis, instead of ethylene glycol, is propylene glycol. It is colored pink or purple and is mostly used in newer car models. Also, they have a longer lifespan, and changing it is not as often as in the case of G11 and G12 classes.

What happens if you mix orange and green antifreeze?

Mixing a G11 antifreeze type, which includes the green one, and a G12 type, where the orange one is included, is the worst possible combination that can be made.

By mixing those two types of antifreeze the consistency of the coolant will thicken leading to clogged pipes, and bad circulation in the cooling system.

Furthermore, the engine and the oil will overheat leading to possible serious damage. The protective properties of those two types of antifreeze will be eliminated in the chemical reaction produced.

Also, the foam will be produced in the expansion tank and system pipes which will cause bearings to wear out faster, the cylinder head to overheat and deform, but also the water pump to fail.

If you have done that mix, you will need a specialist who will thoroughly flush the entire cooling system and then add fresh coolant.

What types of antifreeze can be mixed?

The color of the antifreeze is not a condition for mixing different types of antifreeze, but rather the substances that they are made of.

As I have said above, mixing any coolant from those two types is not allowed, but mixing types of antifreeze is possible under certain circumstances, which I will list below.

Check the label on the antifreeze recipient, it will tell you the class of antifreeze (G11, G12, or G13).

  • mixing G11 with G12 + and G13 is allowed;
  • if absolutely necessary, you can mix coolant G12 with G12 +;
  • it is not recommended to combine G12 with G12 ++ or G13;
  • G12 +, G12 ++ and G13 can be mixed with each other;

Even if you make this combination, when it’s possible you should drain out the mixed composition, flush the cooling system, and add fresh coolant that is recommended by the car manufacturer just for safety reasons.

You can make a few tests by yourself by mixing two different antifreeze. This requires samples from both types that can be mixed in a transparent recipient.

If after 10-15 minutes you do not see any bad reaction such as foam formation, or sediments on the bottom, and the composition has not thickened then this mixing is said to be safe.

One thing you should take into account is that the two types of antifreeze should be heated at 80-90 degrees Celsius or 176 -194 degrees Fahrenheit for the test to be more accurate.


It is not recommended to mix antifreeze of different brands and colors, but there are some situations in which you have to do this. It is important to know that, when mixing, the color is not an important factor, but the chemical composition of the antifreeze, you should mix only identical ones from identical antifreeze classes.

It is important to know that allowed combinations of different antifreeze types are just for emergencies and it is not recommended to continue driving like this after that.

Antifreeze in G11 class and G12 class, should not be mixed, because this can lead to serious engine damage and costly repairs.

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