Coolant — Basic Information (Audi A4 B6)

Coolant consists of a mixture of antifreeze and anticorrosive agent (antifreeze) and water. The anticorrosive agent, which is part of the coolant, prevents the formation of scale, rust and other aggressive corrosive substances in the cooling system. After about four years, this agent loses its effectiveness, after which it must be replaced. However, periodic replacement of coolant has not been prescribed by manufacturers recently. Depending on the antifreeze selected, the proportion of water in the coolant reaches 60%, but this proportion should not fall below 40% even in summer.

Due to its high boiling point under high engine load, the coolant helps to increase the operational safety of the vehicle, especially in countries with hot climates. Freeze protection should be provided down to approximately -25°C (in areas with cold climates, up to approximately -35°C).

All engines are filled with antifreeze G 012 A8 D according to the standard TL VW 774 D, this antifreeze has a red color. This product should never be mixed with the previously used antifreeze G 011 A8 C (green color) or other similar means. Otherwise, serious damage to the engine may occur. Brown coloring of the coolant indicates that it was obtained by mixing different antifreezes. In this case, the coolant must be drained, the engine must be flushed with water (the engine must run for two minutes), then fill in new fluid!