Why do you need antifreeze/coolant in your car?

In the winter we more commonly refer to it as Antifreeze, but why do we need it?

Do I need antifreeze?


As the name suggests, antifreeze actually helps prevent the water in your engine’s cooling system from freezing. The mixture of chemicals lower the temperature at which water freezes. A correctly mixed cooling system will remain liquid well into negative temperatures.


So why is this important and do we actually need antifreeze?

In a word, yes. The antifreeze mixture in your car is actually there to cool the engine, hence why it is also referred to as coolant. The when your engine is running it develops massive amounts of heat through friction and combustion which without cooling would destroy components.

In order to cool the engine the antifreeze needs to circulate around the engine block to the radiator. Without anti-freeze the water in the engine block would freeze.

We all know the horror stories of frozen pipes at home, guess what, the same applies to your engine. Water expands when frozen, water in your engine will expand when frozen, your engine doesn’t like expanding. A frozen engine block could be really bad news. The expansion could cause cracks at weaker parts of the engine block which would most likely write it off.


You should have antifreeze in your cooling system. Do you know the last time yours was changed?

Antifreeze has a service life which will vary dependent upon the type that has been used, whichever, it will gradually become less and less effective at doing its job so it’s important to stay on top of the service schedule.


Can you top up your cooling system with water?

Topping your cooling system with water is OK if that’s all you have access to, but there are a couple of things to bear in mind.

If you are topping up a sealed system, then you have a leak, if you keep topping up with water you are diluting the antifreeze mix further and reducing its effectiveness. So you should really be topping up with antifreeze.

Tap water contains many minerals, such as calcium, which can deposit themselves around your cooling system and cause damage, so you should, in an ideal world be using de-ionised water.


Any questions? Contact us or visit your local branch of Wilco Motosave. We stock top brands of antifreeze/coolant at all our stores and also online at Wilco Direct.

We also offer a FREE Winter Check as part of which we will check your antifreeze strength, so visit your local branch if you are all unsure and we can help.


Engine Cooling