Audi A6 (2001) (C5 4B) 1.9 Tdi must be filled with G12 coolant/antifreeze. You can see it well on the coolant reservoir. G12 antifreeze/coolant is a red colour. You should only use G12 A8D coolant or concentrate TL VW 774D.

If you use G12 Coolant which is red you MUST NOT mix or top up with TL VW 774C coolant specification which is G11 and the colour is blue. G12 conformant coolant should specify one of the conformance levels:

TL VW 774D
TL VW 774F
TL VW 774G

G12 Coolant - red colour.
G12 plus plus - pink.

G12 coolant should only be replaced with a G12 conformant coolant. Conformant coolants are G12, G12 plus and G12 plus plus. I've heard that G13 is a new G12 plus plus name which reduces CO2 emission.


The back label states that Suitable as a filled-for-life filling. G12 plus plus distinguishes itself through the miscibility with the products G12 and G12 plus. Provides protection against, frost, overheating, corrosion and scaling. It is recommended to use the product all-year round. to be used as described only.