Can I mix different colors of antifreeze?

Where does the color of antifreeze come from?

The coolant helps ensure that the vehicle's cooling system functions properly during the cold season. It needs to be changed periodically. And then there is the question of choice. On sale there is a liquid of different brands and various European, American, Asian and Russian manufacturers. Even an experienced motorist cannot always say with certainty how they differ and whether one or another brand is suitable for his car. The various colors of coolants - blue, green, yellow, red, purple - are especially confusing.

The basis of antifreeze is usually a mixture of distilled water and ethylene glycol. Their specific ratio determines the freezing point of the coolant.

In addition, the composition includes various additives - anti-corrosion (corrosion inhibitors), anti-foam and others.

All of these components are colorless. Therefore, in its natural state, almost every antifreeze, together with additives, is a colorless liquid. Color is given to it by safe dyes that help to distinguish antifreeze from other liquids (water, gasoline).

Various standards do not regulate a specific color, but recommend that it be bright, saturated. If fluid leaks, this will help visually determine that the problem is in the car's cooling system.

A little about standards

Many countries have their own national standards. Different manufacturers also have their own specifications for antifreeze. The most famous classification was developed by the Volkswagen concern.

According to it, all antifreezes are divided into 5 categories:

G11 - is produced on the basis of ethylene glycol using traditional (silicate) technology. As anti-corrosion additives, silicates, phosphates and other inorganic substances are used here, which create a protective layer on the inner surface of the cooling system. However, this layer reduces heat transfer and crumbles over time. Nevertheless, such a liquid is quite possible to use, but do not forget to change it every two years.

This class was assigned a blue-green dye color.

Volkswagen also includes the so-called hybrid antifreezes in this class, which can be marked in yellow, orange and other colors.

G12, G12+ - carboxylates are used here as corrosion inhibitors. Such antifreezes are free from the disadvantages of silicone technology and last from three to five years.

The color of the dye is bright red, less often purple.

G12 ++ - antifreezes created using bipolar technology. It happens that they are called lobrid (from the English low-hybrid - low-hybrid). In addition to carboxylates, a small amount of silicon compounds is added to the additives, which additionally protect aluminum alloys. Some manufacturers claim a service life of 10 years or more. But experts recommend replacing every 5 years.

The color is bright red or purple.

G13 - A relatively new type of coolant that appeared a set of years ago. Poisonous ethylene glycol was replaced here by propylene glycol, which is much less harmful to humans and the environment. Additives are similar to G12++.

A yellow or orange dye is usually used as a color marker.

It should be borne in mind that not all European manufacturers adhere to this classification, not to mention Asian and Russian ones.

Mythology

The lack of uniform world standards has given rise to a number of myths that are spread not only by ordinary motorists, but also by car service and car dealership workers. These myths are also actively circulating on the Internet.

Some of them are just related to the color of antifreeze. Many people think that the color of the coolant indicates quality and durability. Some believe that all antifreezes of the same color are interchangeable and can be mixed.

In fact, the color of the coolant has nothing to do with its performance. Often, the same antifreeze can be painted in different colors, depending on the wishes of the particular consumer to whom it is supplied.    

What to consider when buying

When buying antifreeze, the least attention should be paid to its color. Choose a coolant based on the recommendations of your vehicle manufacturer.

For each car, you need to select your own type of coolant, taking into account the characteristics of the cooling system and internal combustion engine. It is important that the antifreeze is of sufficient quality and matches the temperature regime of your internal combustion engine.

The reputation of the manufacturer also matters. Buy products from reputable brands whenever possible. Otherwise, there is a risk of running into a low-quality product, in which, for example, a mixture of glycerin and methanol is used instead of ethylene glycol. Such a liquid has a high viscosity, a low boiling point and, moreover, is very toxic. Its use will cause, in particular, increased corrosion and will eventually damage the pump and radiator.

What to add and whether it is possible to mix

Don't forget to keep an eye on the level of antifreeze. If you need to add a small amount of liquid, it is better to use distilled water, which will not degrade the quality of the antifreeze at all.

If, as a result of a leak, the coolant level has dropped significantly, then antifreeze of the same type, brand and manufacturer should be added. Only in this case the absence of problems is guaranteed.

If it is not known exactly what is poured into the system, then it is best to replace the liquid completely, and not add what was at hand. This will save you from troubles that may not appear immediately.

In antifreezes, even of the same type, but from different manufacturers, different additive packages can be used. Not all of them are compatible with each other and often their interaction can cause degradation of the coolant, deterioration of heat transfer and protective anti-corrosion properties. In the worst case, this can lead to the destruction of the cooling system, overheating of the internal combustion engine, etc.

When mixing antifreezes, in no case should you be guided by color, since the color of the liquid says absolutely nothing about the additives used. Mixing antifreeze of different colors can give an acceptable result, and liquids of the same color can be completely incompatible.

G11 and G12 antifreezes are incompatible and must not be mixed with each other.

G11 and G12+ coolants are compatible, as well as G12++ and G13. Compatibility refers to the possibility of short-term use of such mixtures without serious consequences when the recommended antifreeze is not available. In the future, a complete replacement of the fluid in the cooling system should be made.

A mixture of liquid type G13 with antifreeze G11, G12 and G12 + is acceptable, but due to reduced anti-corrosion properties, it is better not to use it.

To assess compatibility before mixing, you need to pour some liquid from the car's cooling system into a transparent jar and add new antifreeze to it. If no visual changes have occurred, then such fluids can be considered conditionally compatible. Turbidity or precipitation indicates that the components of the additives have entered into a chemical reaction. This mixture should not be used.

It should be remembered that mixing different antifreezes is a forced and temporary measure. The safest option is to completely replace the coolant with a thorough flushing of the system.