2021-2022 Audi Coolant Mixing Guidelines TSB

This Technical Service Bulletin (TSB 2025303/13) from Audi addresses the proper identification and mixing of factory-fill engine coolants across a wide range of models from 2021-2022. It supersedes previous bulletin 19 22-27, dated January 10, 2022, to provide updated information regarding coolant compatibility and usage.

The TSB highlights the discontinuation of certain Audi-approved coolants and the importance of using the correct type to maintain engine health. For owners concerned about their Audi e-tron coolant mixing, or any other Audi model, this document provides crucial information.

Why This TSB Was Issued

Modern combustion engines place higher demands on their cooling systems, necessitating specific coolant formulations. Audi continuously develops its coolants to meet these requirements, and unlike some manufacturers, Audi coolants generally do not require regular changing. However, proper identification and mixing are critical when service is performed.

Audi has introduced several coolant types over the years:

• G11, G12, G12+: These older coolants have been replaced by improved versions.
• G12++: Introduced in Model Year (MY) 2005 for all engines, available for service.
• G13: Introduced in MY 2008 as both initial factory fill and service coolant.
• G12evo: Introduced in MY19 as initial fill and service coolant. This is the recommended coolant for most current models.

Identifying Your Vehicle's Coolant

To determine which coolant your vehicle was filled with from the factory, you can identify it by color. While packaging may vary, the colors are typically:

• G11: Green-blue
• G12: Red
• G12+, G12++, G12evo, G13: Purple

Once identified, you can use the compatibility chart to assess if your vehicle has the correct coolant or if mixing is permissible.

Audi Coolant Mixing Compatibility

The following table, based on Figure 2 in the TSB, details which service coolants can be added to the factory-filled coolant. This is crucial for preventing issues, especially for those needing to understand Audi e-tron coolant mixing.

Can be mixed with:	Green-blue G11 (≥ 1994)	Red G12 (≥ 1996)	Purple G12+ (≥ 2000)	Purple G12++ (≥ 2005)	Purple G13 (≥ 2012)	Purple G12evo (≥ 2018)
G11	Green	Red
G12		Green	Green
G12+		Yellow	Green	Green
G12++		Yellow	Yellow	Green	Green
G13		Yellow	Yellow	Green	Green	Green
G12evo		Yellow	Yellow	Yellow	Green	Green

Color Key:

• Green: Can be mixed in any ratio.
• Yellow: Mixing is possible, but it will cause a reduction in corrosion protection.
• Red: Cannot be mixed.

To use this table, first identify the coolant currently in your cooling system (top row). Then, find the coolant you intend to add (left column). The intersecting cell indicates compatibility. Always prioritize coolants marked in a green field.

Important Warnings and Best Practices

Audi provides several critical warnings and best practices regarding coolant maintenance:

• Reduced Corrosion Protection: