The coolant can come into contact with approx. 100 different materials. For example, it must be compatible with steel, aluminium alloys, grey cast iron, plastics and non-ferrous metals.
Water would actually be a perfect cooling medium if there were no serious disadvantages. Pure water freezes at below 0°C and then expands by about 1/11 of its volume. It develops such high forces that it can blow up cast iron engine blocks. In the event of overheating, water passes into the vapour phase and the cooling effect drops rapidly. It also causes corrosion on bare metals that occur in the cooling circuit. There, scale can form which hinders heat transfer.
In order to prevent these negative properties, antifreeze products are added to the cooling water. Antifreeze products such as Eni Antifreeze Extra D, Eni Antifreeze Special and Eni Antifreeze Special 12++ consist of approx. 90% ethylene glycol, 5 - 7% additives (called inhibitors) and approx. 3 - 5% water. Depending on the specifications of the vehicle manufacturer, the appropriate radiator protection product should be selected. Our antifreeze products are considered to be basically miscible with each other, but mixtures of radiator protection products of different qualities cannot develop their positive properties effectively. The structure of the protective layers in the engine is hindered and the achievable replacement intervals are shortened.
The following points must be observed when handling antifreeze products:
- Care must be taken to fill the cooling system according to type. So if it is not clear which coolant quality is currently in the cooling system, it is advisable to replace it completely instead of refilling it.
- The antifreeze product should be mixed with distilled water at a mixing ratio of 1 : 1 before filling.
- Clean containers should be used.
- The coolants must not be used undiluted because they only have a freezing point of approx. -12°C without the addition of water and there is considerably less heat transfer.
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