CoolantCoolant  - Cooling system - Checking and topping up fluids - General maintenance - Audi A4 Owner's Manual - Audi A4

The purpose of the coolant is to carry heat away from the engine. The correct amount of anti-freeze is important to prevent the cooling system from freezing in winter.

The cooling system is filled for life at the factory, so the coolant does not need to be changed. The coolant consists of a mixture of water and anti-freeze additive G12++. This is a glycol-based anti-freeze with anti-corrosion additives.

Anti-freeze additive

The amount of anti-freeze additive required depends on the temperatures to be expected in the winter season. If the anti-freeze concentration is too low the coolant can freeze, resulting in failure of the cooling system and heater.

The cooling system is filled at the factory with the correct amount of anti-freeze for the country concerned.

In most cases the mixture consists of 60% water and 40% additive. This mixture gives the required anti-freeze protection at temperatures down to -25 ∞C and protects the alloy parts of the cooling system against corrosion. It also prevents scaling and raises the boiling point of the coolant.

Countries with warm climate

The coolant concentration must not be reduced by adding plain water, even in the summer or in warm climates. The concentration of the anti-freeze additive must always be at least 40%.

Countries with cold climate

If greater anti-freeze protection is required in very cold climates, the proportion of the anti-freeze additive G12++ can be increased. A concentration of 60% offers protection down to about - 40 ∞C. The concentration of the anti-freeze additive must not be more than 60%, otherwise this would reduce the anti-freeze protection. In addition, the cooling effect will be adversely affected.

Vehicles for export to countries with a cold climate (such as Sweden, Norway and Finland) are supplied with antifreeze protection down to about -35 ∞C. The concentration of the antifreeze additive for these countries should always be at least 50%.


  • Х It is advisable to have the cooling system checked before the winter season to make sure that the antifreeze concentration is adequate for the conditions to be expected. This applies particularly if you intend to take the car into a colder climate zone. If necessary, have the anti-freeze concentration increased to 50 - 60% as required.
  • Х Use only anti-freeze additive G12++, an additive meeting the specification УTL 774 GФ. Other additives may give considerably inferior corrosion protection. The resulting corrosion in the cooling system can lead to a loss of coolant, causing serious damage to the engine.
  • Х The coolant additive G12++ can be mixed only with additives G12+ and G12.