Antifreeze is essential to ensure cooling of any internal combustion engine. Coolants G11 and G12 differ in additive composition and duration. They are used for different engines and cannot be mixed with each other.
The internal combustion engine gets very hot during operation, because of this, all power units of this type are equipped with a cooling system. There are two types of such systems - air and liquid. On cars, the most often used method of cooling the motors is liquid; on some motorcycles and mopeds, air is found. Water for cooling the mechanism is not convenient - it freezes at air temperatures below zero. Therefore, antifreeze is used as a coolant for engines. Previously, car owners had only one option for antifreeze coolant - antifreeze. Now there are various types of antifreeze. They are marked with two codes - G11 and G12. Fluids vary in color, but the main difference lies in performance, not design.
Antifreeze G11
Green or blue coolant is most commonly produced under the G11 designation. Its composition is based on a mixture of water and ethylene glycol. This is alcohol, it has an oily texture to the touch and is toxic to humans in any dose. In appearance, pure ethylene glycol cannot be distinguished from water - it is transparent, which is why dyes are added to antifreeze. No one will even accidentally confuse a colored liquid with water.
G11 antifreezes contain various additives. They are necessary in order to impart anti-corrosion properties to the mixture and to protect the internal surfaces of the engine from rust. These are inorganic substances - silicates, nitrates, phosphates, borates and their combinations. They are deposited on the metal and form a film that protects against corrosion. But this film in the cooling system reduces heat dissipation, and as a result, the cooling efficiency decreases.
At temperatures above 105 ° C, organic additives begin to decompose. As a result, the anti-corrosion properties of G11 antifreeze are reduced. Dirt builds up in the cooling system due to sediment. The pump, expansion tank valve and other system components are at risk of premature destruction. The circulation of the liquid slows down, the temperature sensors work worse.
Coolant G11 in terms of its characteristics is closest to antifreeze. Its service life does not exceed two years. When replacing antifreeze, the system must be flushed. The advantages of the brand are a modest price, good performance of concentrated G11 antifreezes at low temperatures. It must be remembered that only distilled water, about 5% by volume, can be used to dilute the coolant.
Antifreeze brand G12
The G12 brand is more often produced in red or pink. It includes a range of new generation antifreezes:
- carboxylate antifreeze;
- hybrid antifreezes.
G12 carboxylate antifreeze contains corrosion inhibitors containing carboxylic acids. These are organic substances that can localize the source of rust. They are of two types - they enter into a chemical reaction with a corrosive substance and turn it into harmless compounds, or they cover the corrosion spot with a protective film. These inhibitors do not touch intact metal parts and do not form a dense protective layer that impedes the cooling of the system. Such substances are not destroyed when the motor is heated to operating temperatures.
Hybrid antifreeze brands G12 + and G12 ++ are distinguished by a combination of two types of additives - organic and mineral (silicates or phosphates). Their use is explained by the fact that the cooling system, with only inorganic additives, is not afraid of cavitation, due to which the pump is damaged or the engine block fails. Antifreeze + and ++ include anti-cavitation agents.
G12 coolants provide better protection of the mechanism from rust, and have increased chemical reactivity compared to G11. The duration of use of G12 antifreeze is longer - about 5 years for carboxylate and hybrid versions.
What does the color difference between G11 and G12 mean?
Initially, the Volkswagen Corporation was actively involved in the production of antifreezes, which proposed a classification by color. It was decided that organic coolants would be red or pink and inorganic coolants would be blue and green. However, such a classification was not officially recognized by the standard, therefore, when choosing, one should focus not on the color of the liquid, but on the marking. As a result, the manufacturer can independently choose the color, diluting the range with the colors of his own brand.
In addition to ethylene glycol, antifreeze base can be propylene glycol. It is also an alcohol that is dangerous to humans. Its plus is a small coefficient of thermal expansion. Mixed with water, the composition has a low freezing point. Most often used for G12 coolant. In addition to working additives, antifreeze can contain fluorescent substances, antifoam components and dyes.
What is the Difference Between G11 and G12 Antifreeze
G11 antifreezes contain additives of an inorganic nature, allowing them to be used in engines containing non-ferrous metals. It is with them that corrosion inhibitors of this type react. Brass and copper without a special protective film are quickly destroyed by the action of the glycol base of the coolant.
Antifreeze from the G12 group is used only in systems where only steel and aluminum are used, but no non-ferrous metals. Most modern motors are made from just this material. Their weak point is the formation of a corrosive film at the lowest amounts of moisture. G12 additives must interfere with this process. The technology was named Long Life due to the fact that with such additives, antifreeze lasts much longer.
Can I mix different brands of antifreeze
In most cases, it is impossible to change antifreeze from one type to another. If the engine contains non-ferrous metals, the G12 carboxylate will destroy the protective film. If the question arises about mixing different types of antifreeze, then the answer is unequivocal - it is impossible. When inorganic and organic additives are mixed, they begin to coagulate and a precipitate forms in the liquid.
If necessary, antifreeze of the same type and markings that was in it before can be added to the cooling system. In this case, it is necessary to focus on the characteristics of the composition, and not on its color. That is, it is allowed to add either G11 to G11 based on ethylene glycol, or G12 to G12. You can change the manufacturer, but it is best to stick to the same brand. Otherwise, one should expect the onset of cavitation, the appearance of rust and clogging of the motor channels.
Choice of antifreeze: G11 or G12
To choose antifreeze, it is best to read the vehicle manufacturer's instructions and follow its recommendations. For older cars, in general, antifreeze with the G11 mark can be used. The overwhelming majority of modern cars are produced without non-ferrous metals in their motors, the G12 is suitable for them.
If you use an unsuitable type of antifreeze for the car, the difference will become noticeable at once. The owner will start to worry when the damage to the system becomes significant. Serious damage is possible up to the complete replacement of system elements or the motor itself. Saving in this case does not make sense, since losses in the future during repairs will significantly exceed the difference in prices for consumables.
