The 2019 Audi A6 uses VW Group long-life coolant that meets the TL 774-D specification, commonly sold as G13. It is a purple/pink, phosphate- and silicate-free coolant designed for extended service intervals.
In practice, this means you should refill or top off with G13 coolant only, and you should avoid mixing it with older coolant types such as G11 or G12. If you’re unsure about what is already in your system, consider a coolant flush before switching to G13 to ensure optimal protection and cooling performance.
What the specification means for your A6
The TL 774-D specification identifies a long-life, organic-acid-technology coolant formulated for aluminum engine components common in Audi vehicles. G13 is typically purple or pink in color, designed to resist corrosion, and intended to offer extended service intervals compared with older coolant types.
Compatibility and maintenance notes
Key cautions when topping off or replacing coolant:
Do not mix G13 with older coolant types such as G11, G12, or G12+. If the current coolant in the system is not G13, a full flush is usually recommended before refilling with G13 to ensure proper protection and to avoid potential cooling-system damage.
How to replace or top off coolant on a 2019 A6
Follow these general steps to replace or top off the coolant safely. The steps are guidelines; always consult the owner's manual or a professional if you’re unsure.
- Ensure the engine is completely cool before opening any reservoir or drain plugs.
- Check the coolant level on the reservoir and identify whether a simple top-off is sufficient or a full drain and refill is needed.
- If performing a drain, locate the appropriate drain point or valve and safely remove old coolant into an approved container.
- Fill the system with VW TL 774-D (G13) coolant, using the correct pre-mixed formulation if available, up to the MAX level on the reservoir.
- With the cap off, start the engine and allow it to reach operating temperature to help purge air from the system. Watch the reservoir level and add coolant as needed.
- With the engine cool, recheck the level and inspect for leaks. Top off to the proper level if necessary.
These steps cover typical top-off or full-flush procedures for many 2019 A6 models; for precise torque specs, bleed procedures, and drain locations, consult the factory service manual or a qualified technician.
What to look for when buying G13 coolant
Before purchasing coolant, ensure you pick a product that explicitly meets the VW TL 774-D standard and is compatible with Audi engines. Look for these indicators on the label:
- Designation: G13 (or TL 774-D) approval
- Branding: VW/Audi-approved coolant
- Composition: ethylene glycol-based with organic acid technology (OAT)
- Free from phosphates and silicates
- Color: purple or pink, as commonly associated with G13 formulations
Using the correct coolant is essential for protecting aluminum components, ensuring long-term corrosion resistance, and maintaining the vehicle’s warranty and performance.
Summary
The 2019 Audi A6 requires VW Group long-life coolant that meets TL 774-D, commonly labeled G13. Use only G13-compatible coolant, avoid mixing with older coolant types, and follow proper bleeding and filling procedures to maintain cooling-system integrity. If in doubt, consult the owner's manual or a certified technician to ensure you use the correct formulation for your specific engine and model year.