Car radiator

[Bwian]

There was me thinking it was straightforward.
thanks for all you valuable advice. Ill top up with water or red pending a my service

The coolant also contains inhibitors to help prevent build ups of lime scale, rust and galvanic corrosion (caused by having 2 dissimilar metals connected in your cooling system). Or is that electrolytic corrosion? Always get them confused. It also lubricates the water pump-by diluting it with just water you are compromising its properties and it won't work as effectively. As it gets older it becomes even less effective so it is even more important to use more than just water.