BMW M54B25 Engine

  1. Specifications
  2. Overview, problems
  3. Performance tuning

M54B25 Specs

Manufacturer  Munich Plant
Also called BMW M54
Production 2000-2006
Cylinder block alloy Aluminium
Configuration Straight-6
Valvetrain DOHC
4 valves per cylinder
Piston stroke, mm (inch) 75 (2.95)
Cylinder bore, mm (inch) 84 (3.3)
Compression ratio 10.5
Displacement 2494 cc (152.2 cu in)
Power output 143 kW (192 HP) at 6,000 rpm
Torque output 237 Nm (175 lb·ft) at 3,500 rpm
Redline 6,500 rpm
HP per liter 77
Fuel type Gasoline
ECU Siemens MS43.0
Siemens MS45.0
Siemens MS45.1 (US)
Weight, kg (lbs) ~130 (287)
Fuel consumption, L/100 km (mpg)

for E46 325Ci
13 (18.1)
6.9 (34.1)

9 (26.1)
Turbocharger   Naturally aspirated
Oil consumption , L/1000 km
(qt. per miles)
up to 1.0
(1 qt. per 750 miles)
Recommended engine oil 5W-30
Engine oil capacity, L (qt.) 6.5 (6.9)
Oil change interval, km (miles)  7,000-10,000
Normal engine operating temperature, °C (F) ~95 (203)
Engine lifespan, km (miles)
-Official information

~300 (185)
Tuning, HP
-Max HP
-No life span loss


The engine is installed in BMW 325i E46
BMW 525i E39
BMW 525i E60
BMW X3 E83
BMW Z4 E85

BMW M54B25 engine reliability, problems and repair

This engine is a very popular representative of M54 series which also includes M54B22, M54B30 and S54B32 motors. It firstly appeared in BMW production line in 2000 and turned out to be a great alternative to M52TUB25. However the difference between M54B25 and M54B30 is in their displacement. This is due to the fact that both motors are equipped by different crankshafts, connecting rods and pistons. At the same time they also have different camshafts, intake manifolds, throttles, ECU, injectors and other components.
Cylinder block of the new engine is the same. It is made of aluminum with cast iron sleeves and crankshaft. Connecting rods have also been replaced with longer ones (M54B25 connecting rod length is 145 mm). Engine is equipped with lighter pistons.
Double VANOS cylinder block head is also the same. Long intake manifold has been replaced with a shorter one (-10 mm). Wide ports and channels made it possible to increase power and let engine reveal all its potential. Motor also has electronic throttle control and Siemens MS43/Siemens MS45/Siemens MS45.1 electronic control unit.
This engine was mainly used on BMW models with 25i index.
However, it was not able to take the challenge from new engine versions which appeared from 2005 to 2006. New generation of 2.5-liter engines from N52B25 family turned out to be a better alternative.

BMW M54B25 disadvantages and problems

The most common M54B25 problems include oil leaking. They are the same as M52TU has in the majority of cases. At the same time all drawbacks are also the same as the older M54B30 version has. HERE you can find out more about them.

BMW M54B25 engine tuning

M54B25 3.0 L Stroker. Camshafts

There is no sense in handling with M54B25 engine chip tuning. That is why the easiest way to upgrade this motor is converting M54B25 to M54B30. If you want to increase the level of HP, you will need M54B30 stroker kit which includes crankshaft, connecting rods, pistons, intake manifold, injectros, ECU, throttle body and intake camshaft. Such dimensions will make it possible to increase the level of HP up to 230.
If you want to continue with M54B25 3.0 Stroker modification and receive even more horse power, you need to purchase Schrick sports camshafts (duration 264/248 deg, lift 10.5/10 mm). At the same time you will also need cold air intake and performance exhaust system. When the ECU is tuned properly, your engine will perform from 260 to 270 HP.

M54B25 Turbo

If your aim is construction of M54B25 Turbo, you will need to repeat all operations which were made with M52B28. You will need the same T04E or Garrett GT35 turbo kits with stock internals. Stock pistons and connecting rods are able to handle with up to 400 HP.

M54B25 Supercharger

ESS supercharger kit (Lysholm) can turn out to be a perfect but more expensive alternative to all above mentioned methods of engine upgrade. You can install this kit on yours stock M54 engine without any additional modifications. After the kit is installed, your engine will perform up to 300 HP. It is a perfect decision for the city ride.