BMW

BMW Turbo or Gearbox: two part families, dozens of engine codes not to be confused

Across the BMW range covered here, turbos make up the largest family, ahead of bare engines, gearboxes and transfer cases. The challenge is not finding the part, but identifying precisely which one matches your engine: a single model such as the 3 Series or X3 may have been fitted with several distinct units depending on the year of manufacture and power output, with engine codes that are not interchangeable.

Why the engine code is the only reliable reference

Engine capacity alone is not enough. The 2.0d, the most widely represented engine in this collection, covers codes ranging from the M47D20 to the N47D20 and B47D20 generations, each corresponding to a different architecture with parts that cannot be substituted between them. On the 3.0d, the situation is similar: the M57D30 (306D1, 306D2, 306D3) blocks coexisted with the N57D30 and B57D30 across model years that were sometimes very close together. On the petrol side, the 3.0 encompasses units as different as the N54B30 twin-turbo (used notably on the 335i and xDrive35i), the N55B30 single-turbo and the B58B30 from the next generation. The engine code stamped on the block remains the only reliable reference before placing any order.

Models and part families: where the range is concentrated

The 3 Series dominates the catalogue by a wide margin, followed by the 1 Series and the 5 Series. The X1, X3, X5 and X6 SUVs are also well covered, particularly for the 2.0d and 3.0d diesel engines and the 3.0 petrol units. Transfer cases relate mainly to the xDrive versions of these SUVs and a handful of all-wheel-drive saloons. For gearboxes, the collection is limited to reconditioned 6-speed manuals; no automatic or dual-clutch gearbox is listed within this range. New and reconditioned turbos make up the largest share of the offering, with coverage spanning 1999 to 2024 and references encompassing both the N63B44 V8 twin-turbo found on the 550i, 650i and 750i and the small-displacement turbos for the 1.5i (B38) and 1.6i (N13B16). Browse by model or by engine to go straight to the parts that match your vehicle.