The choice of antifreeze sometimes confuses even experienced motorists. Let’s talk about coolants.
As a rule, the driver learns about the need to change the coolant in the hot summer, when the engine of his car begins to overheat – this can also happen in situations where the level of antifreeze becomes insufficient. But there are so many types of antifreeze on store shelves that choosing the right one is not so easy. What do you need to know?
A bit of history
At the dawn of the automotive industry, ordinary water was poured into engine radiators. Of course, in winter conditions, this imposed additional duties on the driver – before the night parking, the water had to be drained (when freezing, the water expands, which can damage the radiator or tubes), and before the trip, pour it back into the car.
In addition, the parts gradually became covered with scale, which worsened cooling and could clog thin radiator tubes. Finally, a gradual increase in the operating temperature of the motor led to the fact that the water ceased to cope with the function of cooling the engine.
This is how antifreeze appeared – a liquid that does not freeze up to certain temperatures. As a rule, the freezing threshold for standard antifreeze is around -40 degrees, but in regions with a harsh climate, coolants are used that do not freeze up to -65 degrees.
The first antifreezes were created on the basis of methanol or ethanol, but quickly lost their properties due to the boiling off of alcohols. Coolants based on glycerin or calcium chloride did not take root either. Subsequently, ethylene glycol became the main component of antifreezes – its mixture with water provided the necessary resistance to freezing.
However, at high temperatures, ethylene glycol had an increased corrosive effect, which required the introduction of special additives into the coolant composition to prevent damage to hoses, pipes and radiators. The origin of these additives led to the emergence of fundamentally different types of antifreeze. What are they?
With inorganic inhibitors
The first generation of ethylene glycol antifreezes had a package of inhibitor additives (slowing down the corrosion reaction) based on inorganic salts – borates, phosphates, silicates, and so on. When such antifreeze is poured into the engine, salts settle on the internal surfaces of the cooling system and form a film that protects parts from corrosion.
This, by the way, was the Soviet Tosol. It is generally accepted that it was intended only for filling domestic car engines, but this is not so – in its composition it did not differ too much from other antifreezes with inorganic inhibitors.
There are many disadvantages of this type of antifreeze. Firstly, this is a short service life – the same “Tosol” was ordered to be changed every 1-3 years or 60 thousand kilometers. Secondly, the film formed by salts impairs heat transfer, and inorganic compounds are destroyed when the temperature rises above 105 degrees. Therefore, in modern engines with high operating temperatures, such a coolant cannot be used. And wear products, which are a suspension of solid particles, “hit” the water pump.
With organic inhibitors (carboxylate)
The tightening of environmental requirements led to an increase in the temperature regime of engines, so that the shortcomings of the “traditional” type of antifreeze became more and more obvious. And for the new engines, a coolant was developed with corrosion inhibitors based on metal salts of carboxylic acids – the so-called carboxylate antifreezes.
Carboxylate antifreezes differ from the previous generation of coolants in their extended service life (up to 5 years) and better protect metal parts from corrosion and cavitation. But they also have better fluidity, which leads to leaks at the slightest leak in the system.
WOG CARBOXYLATE ANTIFREZE Antifreeze carboxylate red ready G12+ (5L)
In addition, when filling it with a cooling system in which antifreeze with inorganic inhibitors previously worked, the additives interact. As a result, this leads to irrational consumption of organic acid compounds contained in it and a reduction in service life, and in some cases, accumulation of a fine suspension in the cooling system can occur, which sharply reduces the anti-foam and anti-cavitation properties of carboxylate antifreeze.
Because of this, carboxylate antifreezes should be used mainly in new cars, the cooling system of which was originally filled with this type of antifreeze from the factory. Switching from a previous generation of antifreeze to carboxylate requires flushing the cooling system and replacing old seals and hoses that can cause coolant to leak. Mixing antifreezes of various types is strongly discouraged.
hybrid
The next step in the progress of coolants is the emergence of hybrid antifreezes. A mixed package of additives has been added to them – the basis is inorganic salts, and the rest is carboxylates.
Therefore, hybrid type antifreeze provides combined protection – additives based on inorganic salts immediately settle on the walls of parts and prevent their corrosion. And the carboxylate part reacts in those places where the protective coating is damaged.
Antifreeze Coolstream Hybrid Extra
Of course, hybrid antifreezes combine the disadvantages of both types. Thick protective coating impairs cooling performance. But such a coolant also lasts longer than with inorganic inhibitors.
Lobrid
The latest generation of ethylene glycol-based antifreezes at the moment (more expensive, but also safer polypropylene can be used). They contain organic corrosion inhibitors combined with silicon compounds to provide additional protection to aluminum alloys. This is true for the engines of modern cars, the cylinder blocks of which are mainly cast from “winged metal”.
Antifreeze lobrid fluorescent -40°C, Si-OAT, G12++, 5l/5.36kg L2018002 Carville Racing
, lobrid antifreeze, purple, freezing point -43°C, VAG index G-12++
The increased boiling point (up to 135 degrees) of lobrid antifreezes allows them to be used in the most heat-loaded modern engines. The declared service life of such antifreezes can reach 10 years or up to 200 thousand km (that is, the factory refueling of the cooling system is considered “for life”, for the entire life of the car).
How to determine which antifreeze your car needs
Some motorists are guided by the color of antifreeze, but it’s better not to do this! The coolant itself is transparent, and manufacturers add dyes to make it easier to control its level, look for leaks, and also “bind” consumers to a specific brand of antifreeze.
The classification introduced by Volkswagen is widely used. Hybrid antifreeze is indicated by the G11 index and is green. Organic G12 and G12+ have a red dye. And modern G12 ++ and G13 lobrid coolants are purple. However, different manufacturers can change colors – there is still no general standard in the industry.
Source: Wodthikorn Phutthasatchathum
Therefore, it is best to navigate by the accompanying documentation for the machine – the instruction manual, service book or plates on the body, where an alphanumeric code or antifreeze manufacturer (trademark) can be indicated. If all of the above is missing, search engines will help.
Is it possible to mix antifreezes
Mixing different antifreezes is not recommended, as the interaction of the additives contained in them can significantly reduce the characteristics of the coolant or its service life. And, for example, the same VW concern directly prohibits mixing antifreezes of categories G11 and G12.
If you know exactly what kind of antifreeze is poured into your car’s engine, then it is best to continue using the same specific coolant when replacing. If suddenly an unplanned leak occurs or the level of antifreeze just drops, but you don’t know its brand or you don’t have the right one in the store, then you can add distilled water. And at the first opportunity to replace the entire fluid.
Do I need to change antifreeze often?
Here you should be guided by the operating instructions for the car or service recommendations. Of course, the service life primarily depends on the type of antifreeze – in the case of using modern lobrid fluids, it may not be needed in principle. But if the antifreeze has become cloudy, oil stains are noticeable on its surface, or you suddenly had to mix two different coolants, then you need to change the entire antifreeze as soon as possible.
