Antifreeze
Antifreeze is a glycol-based additive that stops coolant freezing in winter and boiling in summer while also protecting the cooling circuit from corrosion.
Prepared by the Bicops Technical Content Team · Last updated:
Shop AntifreezeWhat does it do?
Pure water freezes at zero and can crack the block as it expands. An antifreeze mixture lowers the freezing point to around -30 degrees and raises the boiling point. Its inhibitors also protect the aluminium block, radiator and heater matrix from corrosion; because that protection depletes over time, antifreeze cannot be used indefinitely.
Colours and types
Colour alone does not indicate a standard; what matters is the technology the manufacturer requires (for example G11, G12, G12++ or G13). Mixing two antifreezes of different technologies can cause the inhibitors to precipitate and gel. If you are unsure, drain the system and refill with the single type the car requires.
Mixing and replacement
Concentrated antifreeze is usually mixed 50/50 with distilled water; the lime in tap water leaves deposits in the radiator and heater matrix. Ready-mixed products are poured in directly. The change interval is 2-5 years depending on type; if the fluid has gone cloudy or contains oil traces or sediment, renew it without waiting for the mileage.
Frequently Asked Questions
Can water be used instead of antifreeze?
It can be added in an emergency to complete a journey, but permanent use creates freezing and corrosion risk. Replace it with the correct mixture as soon as possible.
Can antifreezes of different colours be mixed?
Not recommended. Technology, not colour, is decisive, and incompatible inhibitors can precipitate and block circulation.
What if the antifreeze level keeps dropping?
There is no consumption in a sealed system. Look for a leak at the water pump seal, radiator, hoses or cylinder head gasket.