BMW N55 Engine (N55B30)

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

N55 Specs

Manufacturer  Munich Plant
Also called BMW N55
Production 2009-present
Cylinder block alloy Aluminium
Configuration Straight-6
Valvetrain DOHC
4 valves per cylinder
Piston stroke, mm (inch) 89.6 (3.53)
Cylinder bore, mm (inch) 84 (3.3)
Compression ratio 10.2
Displacement 2979 cc (181.8 cu in)
Power output 225 kW (306 HP) at 5,800-6,000 rpm
235 kW (320 HP) at 5,800-6,000 rpm
240 kW (326 HP) at 5,800-6,000 rpm
250 kW (340 HP) at 5,800-6,000 rpm
Torque output 400 Nm (295 lb·ft) at 1,200-5,000 rpm
450 Nm (332 lb·ft) at 1,300-4,500 rpm
450 Nm (332 lb·ft) at 1,300-4,500 rpm
450 Nm (332 lb·ft) at 1,300-4,500 rpm
Redline 7,000 rpm
HP per liter 102.7
Fuel type Gasoline
ECU Bosch MEVD17.2
Weight, kg (lbs) ~132 (290)
Fuel consumption, L/100 km (mpg)

for E92 335i
12.0 (19.6)
6.3 (37.3)

8.4 (28)
Turbocharger Turbocharged
Borg Warner B03 Twin Scroll
Oil consumption , L/1000 km
(qt. per miles)
up to 0.7
(1 qt. per 850 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) ~110 (230)
Engine lifespan, km (miles)
-Official information

Tuning, HP
-Max HP
-No life span loss


The engine is installed in BMW 135i E82/E88
BMW M135i F20
BMW M235i F22/F23
BMW 335i E90/E91/E92/E93
BMW 335i F30/F31
BMW 435i F32/F33/F36
BMW 535i F10/F11
BMW 640i F12/F13
BMW 740i F01
BMW X1 E84
BMW X3 F25
BMW X4 F26
BMW X5 E70
BMW X5 F15
BMW X6 E71
BMW X6 F16
BMW 335 GT F34
BMW 535 GT F07

BMW N55 engine reliability, problems and repair

This is another representative of new gen 6-cylinder engines which was produced in 2009. It was supposed to be replacement for N54B30, N53B30 and N62B40 motors. It has the same cylinder block as in N54 which is made of aluminum with cast iron sleeves equipped by oil injectors. At the same time N55 is equipped with lighter crankshaft in comparison with N54. It is 3kg lighter (20.3 kg). Pistons and connecting rods were modified. The length of connecting rods is 144.35 mm.
Cylinder block head was also improved. Double-VANOS variable valve timing on the intake and exhaust shafts system was modifed. At the same time variable valve lift system Valvetronic III appeared. Diameter of inlet valves is 32mm, exhaust valves are 28 mm in diameter. BMW N55 camshafts characteristics are as follows: duration 255/261 deg, lift 9.9/9.7 mm.
Inlet and outlet systems have also been improved.
Twin turbo configuration has been replaced by Twin scroll which means that new Borg Warner B03 turbocharger has two exhaust gas inlets and two impellers. Such turbocharger is able to provide engine with a boost much earlier as well as provide it with maximum of rpm starting from 1,200 rpm. Boost pressure is 0.65 bars/9.5 PSI.
Previous engine control unit was replaced with Bosch MEVD17.2.
N55B30 motor was used in BMW 35i and 40i models.
At the same time N55 was used as a base for creation S55 sports engine which was developed by BMW M GmbH department for M3 and M4 sport cars.

BMW N55 engine modifications and differences

1. N55B30M0 (2009 – present) is a basic version of engine with the following specs: Power – 306 HP at 5,800-6,000 rpm, 400 Nm of torque at 1,200-5,000 rpm. It was used for BMW models with 35i index.
2. N55 (2010 – present ) is a new version with the following specs: Power – 320 HP at 5,800-6,000 rpm, 450 Nm of torque at 1,300-4,500 rpm. It was used for BMW models with 35i and 40i index.
3. N55B30O0 (2011 – present) is equal to N55 and has the following specs: Power – 326 HP at 5,800-6,000 rpm, 450 Nm of torque at 1,300-4,500 rpm. It was used for BMW models with 35i index.
4. N55HP (2011 – present) is another version with the following specs: Power – 340 HP at 5,800-6,000 rpm, 450 Nm of torque at 1,300-4,500 rpm (Overboost 500 Nm). It was used for BMW models with 35i index.

BMW N55 engine problems and drawbacks

1. High level of oil consumption in N55. Such problem is mainly caused by crankcase vent valve (PCV). Check it first of all.
2. Misfire. Such malfunction is likely to result in carbonized hydraulic lifters. Check them and use high quality engine oil.
3. Engine vibration. It can result in the fact that fuel injectors are out of order. The duration period is about 80,000 km (50,000 miles) of mileage. All you need is to replace them to make motor operate properly.
In addition the problem with high pressure fuel pump (HPFP), still exists in N55 engines. The pump may get out of order regularly. At the same time it is not surprising that motor needs only high quality fuel and oil.
Apart from abovementioned possible problems N55 engine is perfect. It has high level of reliability; it is rather powerful with long lifespan. At the same time it is perfect for tuning. Purchasing of N55 will certainly turn out to be a good idea.

BMW N55 engine tuning

N55 Turbo upgrade. Stage 1-2

New N55 version can be upgraded equally to previous N54 generation of engines. BMS JB4 Stage 2 firmware with downpipes will provide you with up to 360 HP.
If you additionally buy cold air intake (for example, Burger Motorsports) along with performance exhaust system, you will get 380 HP. These are the most appropriate upgrades for such engine. They will help to keep the level of motor reliability high enough. When all modifications are over your BMW will cover quarter mile distance in 11.8-11.9 seconds. Stock version of BMW 135i N55 covers ¼ mile in 13.3-13.5 seconds. The difference is obvious.

Next stage of power increase is connected with replacement of turbochargers and purchasing of Methanol Injection Kit. Note that costs will be higher for obtaining 450 HP engine.