Comment. Some coolants use the less toxic propylene glycol instead of ethylene glycol. Propylene glycol-based coolants are not widely used due to the high cost of propylene glycol and the deterioration of the heat dissipation properties of the fluid. All antifreezes are more or less poisonous, be careful! In addition, antifreeze leaves indelible stains on the body enamel; if it gets on the paintwork, it should be removed immediately and the surface washed with clean water.
The coolant must meet the following basic requirements:
- remove heat from the engine cylinders;
- do not freeze at low temperatures;
- do not form deposits in the cooling system;
- do not cause corrosion of metal parts and do not destroy the rubber elements of the cooling system;
- do not foam during operation.
Fulfillment of these requirements is achieved by adding a special complex of additives.
Antifreezes according to the composition of additives are divided into traditional (Traditional coolants or Conventional coolants), hybrid (Hybrid coolants) and carboxylate types.
Warning! It is not recommended to mix antifreezes of different brands during the topping up process, and those having different bases are generally unacceptable! Do not fill the system with clean water, even distilled and even in summer. Firstly, it is possible, forgetting about it, to ruin the engine already in the October frosts; secondly, most likely, it will not be possible to avoid corrosion and destructive cavitation * in the system, this is how modern engines are arranged. Finally, pure water has poor lubricity and the pump seal will wear out quickly.
* Cavitation is the formation of gas-vapor bubbles in a liquid flow. Disappearing, these bubbles cause microscopic explosions that destroy the walls of pipelines and other parts washed by the flow.
Comment. Carboxylate antifreeze has a longer service life and, compared to traditional and hybrid antifreezes, protects parts of the engine cooling system from corrosion better than traditional and hybrid antifreezes.
To indicate the type of antifreeze, many manufacturers use the standard adopted by the VAG group:
- G11 - hybrid antifreeze;
- G12 and G12+ are carboxylate antifreezes.
In 2008, a new type of antifreeze appeared, in which an organic base is combined with a small amount of mineral corrosion inhibitors. They have not yet established a generally accepted designation. The developers of antifreeze gave it the name Lobrid coolants and SOAT coolants. This antifreeze has a G12++ standard (according to the specification of the VAG group).
Various dyes are added to antifreezes, giving the antifreeze one or another color, which does not affect its operational and chemical properties. Therefore, when choosing antifreeze, attention should not be paid to its color, but to its chemical composition (type), recommended by the vehicle manufacturer.
On sale there are both ready-to-use antifreezes and concentrated ones, which must be diluted with distilled water in a certain proportion before use. The proportions for diluting antifreeze with distilled water are usually indicated on the label attached to the container.
Comment. Dilute antifreeze with distilled water before pouring into the cooling system. This is the only way to ensure that the indicated ratios of antifreeze and distilled water are exactly observed. Check the density of antifreeze after mixing.
In the vehicle cooling system, the manufacturer recommends the use of Type D antifreeze based on a mixture of water and ethylene glycol.