Mazda Cosmo/121 (EU)

Manual transmission fluid capacity & service interval

Mazda Cosmo/121 (EU) manual transmission fluid capacity is 1,7 liters. Service intervals include checks every 10000 km or 6 months, changes every 20000 km or 12 months, and an initial change at 1000 km. The data covers 4 configurations.

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

TypeSpecifications
Cosmo/121 1800, CD (1975-1981)
  • Use: Normal
  • Capacity 1,7 liter
  • Check 10000 km/ 6 months
  • Change 20000 km/ 12 months
  • Code: 5/1
Cosmo/121 1800, CD (1975-1981)
  • Use: Initial service
  • Capacity 1,7 liter
  • Change 1000 km
  • Code: 5/1
Cosmo/121 2000, CD (1975-1981)
  • Use: Normal
  • Capacity 1,7 liter
  • Check 10000 km/ 6 months
  • Change 20000 km/ 12 months
  • Code: 5/1
Cosmo/121 2000, CD (1975-1981)
  • Use: Initial service
  • Capacity 1,7 liter
  • Change 1000 km
  • Code: 5/1

Additional Notes

  • The Mazda Cosmo/121 manual transmission holds 1.7 liters of fluid across both the 1800 and 2000 engine variants produced from 1975-1981, indicating a consistent gearbox unit shared between the two displacements.
  • Under normal use conditions, the 1800 CD calls for a fluid check every 10,000 km or 6 months, whichever comes first, with a full fluid change scheduled at 20,000 km or 12 months.
  • The 2000 CD follows the same normal-use interval structure as the 1800 CD, with checks at 10,000 km or 6 months and changes at 20,000 km or 12 months.
  • Both the 1800 and 2000 CD variants share an initial service interval requiring a fluid change at just 1,000 km, a practice associated with flushing metal particles generated during the break-in period of new gear surfaces.
  • The 1.7-liter capacity figure applies equally to both the initial service and normal service fills for all 1975-1981 Cosmo/121 manual transmission configurations, meaning no partial-drain procedure is specified for either service type.

Other Systems