In concentrated form, ethylene glycol has high corrosive activity, its boiling point is +170°C. Due to the fact that the crystallization temperature of ethylene glycol in concentrated form is -20°C, to lower the crystallization temperature it is diluted with distilled water (Table 13.1).
To neutralize the corrosive activity, special additives are added to ethylene glycol. To distinguish it from other operating fluids and to make it easier to determine the level in the expansion tank of the engine cooling system, a dye is added to the antifreeze.
Table 13.1 Ethylene glycol concentration depending on the required crystallization temperature of antifreeze
