I have just done a bit of research from various companies on VW coolants.
VW Coolant Comparison
- G11 mixes well with G12+, G12++ or G13 but not with G12.
- G12 mixes well with G12+, G12++ and G13 but not with G11.
- G12+ mixes well with G12++ and G13, also with G11 and G12 but there is a loss of corrosion protection.
- G12++ mixes well with G13, also with G11, G12 and G12+ but there is a loss of corrosion protection.
- G13 mixes well with G12++, also with G11, G12 and G12+ but there is a loss of corrosion protection.
VW Coolant Comparison