When should you change coolant — and can you mix types?
Coolant is not just for winter. The same fluid raises the boiling point in summer and protects the radiator, water pump and engine against corrosion all year.
When to change it
- Conventional (silicate) coolants: about every two years or 40,000 km.
- Long-life coolants (OAT and HOAT): usually up to five years or more, per the manufacturer.
Change it straight away if it looks cloudy or brown, contains rust particles, has an oily film or smells unusual.
The right mix
For most regions a 50/50 mix of concentrate and distilled or demineralised water is right, protecting down to about −35 °C. Neat concentrate does not work better and transfers heat less well. Pre-diluted coolants are poured in as they are.
Can I use tap water?
Tap water contains minerals that leave scale in the radiator, and without antifreeze it offers no protection against corrosion or freezing. It is fine in an emergency, but refill with the correct mix as soon as you can.
Mixing coolants
Coolant colour is not standardised and does not tell you the type. Mixing a conventional coolant with an OAT coolant can weaken corrosion protection or form deposits. If you do not know what is in the car, drain, flush and refill with one type.
Quick answers
How often should coolant be changed?
Can I mix green and pink coolant?
What is the right coolant-to-water ratio?
See our coolants & brake fluids range, or ask our sales team for a recommendation and price.
