BMW 8 series, E31 (EU)

Manual transmission fluid capacity & service interval

BMW 8 series, E31 (EU) manual transmission fluid capacity ranges from 1,75 to 2,3 liters. The data covers 6 configurations.

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

Type	Specifications
840Ci (1995-1999)	Use: Normal Capacity 1,75 liter Code: 6/1
850CSi (1994-1997)	Use: Normal Capacity 2,3 liter Code: 6/1
840Ci (1993-1996)	Use: Normal Capacity 1,75 liter Code: 6/1
850Ci (1992-1994)	Use: Normal Capacity 2,3 liter Code: 6/1
850CSi (1992-1994)	Use: Normal Capacity 2,3 liter Code: 6/1
850i (1990-1992)	Use: Normal Capacity 2,3 liter Code: 6/1

The BMW 8 Series E31 manual transmission fluid capacities split into two distinct values across the lineup: 1.75 liters for the 840Ci and 2.3 liters for all V12-engined variants, including the 850i, 850Ci, and 850CSi.
The higher 2.3-liter capacity in the V12 models reflects a larger gearbox unit paired to the more powerful engine, requiring a greater fluid volume to maintain adequate lubrication across all internal components.
The 840Ci, available in two overlapping production spans covering 1993-1996 and 1995-1999, carries a consistent 1.75-liter manual transmission fluid capacity across both entries, indicating no change in gearbox specification between those periods.
The 850CSi is listed across two separate year ranges, 1992-1994 and 1994-1997, both specifying the same 2.3-liter capacity, pointing to a stable transmission design throughout the model's production run.
All six rows carry a normal use condition, meaning the listed capacities apply to standard operating environments rather than severe-duty or high-stress driving cycles.
The 850i, produced from 1990-1992, shares the 2.3-liter manual transmission fluid capacity with the later 850Ci (1992-1994), suggesting continuity in the gearbox used across the early V12 coupe variants.