Audi A6, S6, RS 6, 4A2 / 4A5 (USA)

Brake fluid capacity & service interval

Audi A6, S6, RS 6, 4A2 / 4A5 (USA) models utilize brake fluid with a capacity of 1 liter. Service intervals include checking every 10000 miles or 12 months and changing every 24 months. The data covers 6 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
RS 6 Performance TFSI quattro (463 kW) (2023- )
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A6 45 TFSI quattro (195 kW) (2021- )
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
RS 6 TFSI quattro (441 kW) (2021-2023)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
S6 TFSI quattro (331 kW) (2019- )
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A6 45 TFSI quattro (185 kW) (2018-2021)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A6 55 TFSI quattro (250 kW) (2018- )
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months

Additional Notes

  • A 1-liter brake fluid capacity is consistent across all A6, S6, and RS 6 configurations listed, spanning output levels from 185 kW to 463 kW. In brake system servicing, this figure represents the total fluid volume held within the reservoir, lines, and calipers rather than a flush quantity, so actual fluid consumed during a change may be less depending on system condition.
  • The check interval of 10,000 miles or 12 months, whichever comes first, applies under normal use conditions across every listed configuration. Brake fluid checks at this frequency are intended to monitor moisture absorption, since glycol-based brake fluids are hygroscopic and gradually absorb water from the atmosphere, which lowers the fluid's boiling point over time.
  • The 24-month change interval is uniform across all six configurations regardless of engine output or trim level. A time-based interval rather than a mileage-based one reflects the hygroscopic nature of brake fluid, where degradation is driven primarily by elapsed time and atmospheric exposure rather than distance traveled.
  • The A6 45 TFSI quattro saw a power output revision from 185 kW to 195 kW starting in 2021, yet the brake fluid capacity and service intervals remain unchanged between the two variants. This indicates the brake system architecture was not altered in a way that affected fluid volume or maintenance scheduling at that update point.
  • The RS 6 TFSI quattro at 441 kW covers the 2021-2023 model years, while the RS 6 Performance TFSI quattro at 463 kW carries a 2023 start year. Both share the same 1-liter capacity and identical check and change intervals despite the 22 kW difference in rated output, suggesting the brake system specifications were carried over to the higher-output Performance variant.
  • The S6 TFSI quattro at 331 kW, introduced for the 2019 model year, shares the same brake fluid service schedule as the A6 variants that began in 2018. The one-year offset in introduction dates between the S6 and the base A6 configurations did not result in any differentiation in brake system fluid capacity or maintenance intervals.

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