Porsche 928 (EU)

Automatic transmission fluid capacity & service interval

Porsche 928 (EU) automatic transmission fluid has a capacity range of 5,5 to 9,3 liters. Service intervals include checks at 20000 km or 12 months and changes at 40000 km or up to 48 months. The data covers 6 configurations.

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

TypeSpecifications
928 GTS (1991-1995)
  • Use: Normal
  • Capacity 9,3 liter (Dry fill)
  • Capacity 7,3 liter (Service fill)
  • Check 20000 km
  • Change 40000 km/ 24 months
  • Code: 4/1
928 GT (1989-1992)
  • Use: Normal
  • Capacity 9,3 liter (Dry fill)
  • Capacity 7,3 liter (Service fill)
  • Check 20000 km/ 12 months
  • Change 40000 km/ 48 months
  • Code: 4/1
928 S4 (1986-1992)
  • Use: Normal
  • Capacity 9,3 liter (Dry fill)
  • Capacity 7,3 liter (Service fill)
  • Check 20000 km/ 12 months
  • Change 40000 km/ 48 months
  • Code: 4/1
928 S (1984-1986)
  • Use: Normal
  • Capacity 5,5 liter
  • Check 20000 km/ 12 months
  • Change 40000 km
  • Code: 3/1
928 S (1980-1984)
  • Use: Normal
  • Capacity 5,5 liter
  • Check 20000 km/ 12 months
  • Change 40000 km
  • Code: 3/1
928 (1977-1982)
  • Use: Normal
  • Capacity 5,5 liter
  • Check 20000 km/ 12 months
  • Change 40000 km
  • Code: 3/1

Additional Notes

  • The Porsche 928 (1977-1982) and 928 S (1980-1986) share a single capacity figure of 5.5 liters for the automatic transaxle, with no distinction between dry fill and service fill volumes. A single figure of this kind typically represents the total fluid volume used during a standard service drain-and-refill procedure.
  • Starting with the 928 S4 (1986-1992), the automatic transaxle specifications introduce two separate capacity values: 9.3 liters for a dry fill and 7.3 liters for a service fill. The dry fill figure applies when the transmission and torque converter are completely empty, such as after a full overhaul, while the service fill figure reflects the smaller volume needed when residual fluid remains in the torque converter during a routine fluid change.
  • The 928 GT (1989-1992) and 928 GTS (1991-1995) carry the same 9.3-liter dry fill and 7.3-liter service fill capacities as the 928 S4, indicating a consistent transaxle unit across the later variants of the model range.
  • The fluid check interval across all six configurations is set at 20,000 km. The earlier 928, 928 S, and 928 S4 rows also attach a 12-month time limit to the check interval, meaning whichever threshold is reached first would trigger the inspection.
  • The 928 GTS (1991-1995) check interval specification lists only the 20,000 km distance without an accompanying time-based limit, which differs from the 12-month pairing seen in the earlier configurations.
  • The fluid change interval for the 1977-1982 928 and both 928 S variants (1980-1984 and 1984-1986) is stated as 40,000 km with no time-based limit attached, leaving distance as the sole trigger for a scheduled fluid change.
  • The 928 S4 and 928 GT both carry a change interval of 40,000 km or 48 months, meaning a fluid change is due after approximately four years even if the distance threshold has not been reached. The 48-month time limit reflects the degradation of automatic transmission fluid over time independent of mileage accumulation.
  • The 928 GTS (1991-1995) shares the 40,000 km change distance with the 928 S4 and 928 GT but pairs it with a shorter 24-month time limit rather than 48 months, making the time-based change interval twice as frequent as on the preceding S4 and GT specifications.

Other Systems