Why is ethylene glycol antifreeze used in car engine cooling systems?

Owing to its high boiling point and non-flammable properties, ethylene glycol coolant additive has become mainstream in the car engine cooling system.

In the formulation of vehicle antifreeze additives, ethylene glycol (MEG) antifreeze can prevent the engine from freezing in winter and overheating in summer. When mixed with water at the appropriate ratio, ethylene glycol antifreeze can reduce the freezing point to -45°C ~ -50°C and even lower. At the same time, the coolant corrosion inhibitor can improve the boiling point, ensuring the engine's excellent performance over the year.

 

Why use ethylene glycol (MEG) as the base for coolant corrosion inhibitors?

 

The shortages of traditional anti-freeze additives:

Ethanol (alcohol): low boiling point leads to significant evaporative loss and a fire risk in summer. Its efficiency in formulating a low freezing point mixture is inferior to that of ethylene glycol. 

Glycerin (glycerol): excessively high viscosity and poor fluidity, combined with relatively high cost.

Inorganic salts (sodium chloride, calcium): low cost but highly corrosive to metals, suitable only for open expendable systems.

Because of that, ethylene glycol antifreeze has become a widely used coolant additive in engine vehicle cooling systems, industrial cooling systems, and freeze protection for winter construction at home and abroad.

 

The advantages of water-glycol antifreeze

1. Low freezing point: the freezing point of pure ethylene glycol is about -11 to -13℃. After mixing it with water, the freezing point will decrease a lot.

2. High boiling point, suitable for both winter and summer: the ethylene glycol has a high boiling point over 197 ℃, formulated with water, the boiling point of the whole liquid is higher than water. This prevents the engine cooling system from boiling over during summer and, by combining both antifreeze and anti-boil capabilities, allows for year-round use without replacement.

3. Low evaporation loss: Ethylene glycol is virtually non-volatile at normal operating temperatures; the main evaporation loss in the cooling system is water, not the ethylene glycol itself. Therefore, routine maintenance only requires adding water and does not require frequent antifreeze changes.

It is not true that the more ethylene glycol, the lower the freeze point is. When the content is at about 60%, the freezing point rises.

 

Therefore, the practical formulation should be based on the local lowest temperature, and the common freeze point of the coolant additive should be lower than 5-10℃ than the local lowest temperature.

 

*Noted that the ethylene glycol is highly toxic to mammals (with an oral LD50 in humans of approximately 786 mg/kg).

It's sweet and easy to ingest accidentally. The MEG can be absorbed through the gastrointestinal tract and skin, through the respiratory tract. Therefore, when use is necessary, take appropriate protective measures and prohibit ingestion.

 

Chorus vehicle engine cooling system anti-freeze solutions:

Ethylene glycol coolant additive systems are corrosive to metals, particularly to materials that are commonly used in cooling systems, such as carbon steel, cast iron, cast aluminum, copper, brass, and solder. Without corrosion inhibition measures, the corrosiveness of ethylene glycol antifreeze would significantly reduce the system's service life. Therefore, corrosion inhibitors must be added to the antifreeze to prevent it from corroding cooling lines and equipment.

Chorus is a professional engine vehicle additive and packages supplier in China. Chorus's  Ethylene Glycol (MEG) for Coolant is an important organic compound widely formulated in automotive antifreeze and engine coolant. In car antifreeze formulations, ethylene glycol effectively prevents engines from freezing in winter and overheating in summer. Combined with the corrosion-inhibitor additives, the ethylene glycol (MEG) antifreeze additive solution can protect radiators, pipes, and other metal components from corrosion.

 

We can also offer you ethylene glycol antifreeze and corrosion inhibitors, including Organic Acid Technology (OAT) corrosion inhibitor package and Hybrid Organic Acid Technology (HOAT) antifreeze corrosion inhibitors, which protect metals and other parts from corrosion to prolong the service life of the vehicle's cooling system.

 

Contact us to get the latest information and quotation.