What does antifreeze do for your car

Maintaining your car is far simpler now than ever before. Most cars go through very tough cold weather testing programmes before they’re brought to market and they’re built to withstand the harshest climates. For these reasons, drivers tend to get lazy and not worry about changing the oil and topping up the water. Putting antifreeze into the engine is another thing that drivers tend to neglect. If you’re asking: what does antifreeze do for your car, you’ll be surprised to read just how important it can be.
    Wikimedia commons - Brian Snelson


Preventing corrosion and scale build up in the cooling system is very important as more than 60% of engine failures are attributed to the cooling system. Antifreeze is multi-functional and it’s vital to the operation of any engine. Modern coolants and antifreezes perform the following functions.

  • Prevent corrosion
  • Help heat transfer
  • Prevent scale build up

In order to perform well an antifreeze must be –

  • Stability at high temperature
  • Compatibility with plastics and elastomers used in the engine
  • Low foaming

Which one to use

The coolant / antifreeze recommended by the car’s manufacturer is the best one to use. If you car’s in warranty, any topping up of the antifreeze during any service work carried out will have been done using this brand or a suitable alternative that meets the original specification. Even when the warrant period is over it’s still best to use the same antifreeze product.


The concentrate antifreeze is diluted with water before use and to ensure protection for the cooling system, a concentration of between 40% and 50% (by volume) is recommended. Introducing water to the antifreeze can be an issue because the quality of the water can reduce the antifreeze’s effectiveness. High levels of calcium and magnesium in tap water can lead to scale build up in the engine’s cooling system. In hard water areas, you should use distilled or deionised water instead.

United Kingdom - Excite Network Copyright ©1995 - 2020