Coolant, Draining And Filling: Filling
The water portion of the coolant influences the effectiveness of the coolant. Volkswagen has decided to define the water quality used in the cooling system based on the different mixtures and country and regional requirements. Use distilled water.
Use only coolant additives. Other coolant additives may above all reduce the corrosion protection effect significantly. The damage resulting from this may lead to loss of coolant and consequently to severe engine damage.
Coolant with the correct mixture ratio prevents freezing and corrosion damage and calcium deposits. The boiling point will be raised. The cooling system must be filled with coolant additive year-round.
Because of its high boiling point, the coolant contributes to engine reliability under heavy loads, particularly in countries with tropical climates.
Freeze protection must be guaranteed down to approximately -25°C (-13°F) (in arctic climatic countries down to approximately -36°C (-32.8°F)).
The coolant concentration must not be reduced by adding water even in warmer seasons and in warmer countries. The coolant additive portion must be at least 40%.
If a lower freeze protection is necessary due to the climatic conditions, increase the amount of coolant additive. The maximum amount is 60%. If the amount is increased beyond that, the freeze protection will be reduced and cooling effect will be reduced.
The Refractometer T10007A MUST be used to determine the freeze protection density.
Read the freeze protection value on the scale for the coolant additive that has been added.
Do not reuse used coolant.