BMW N55 explained

The BMW N55 is a turbocharged straight-six petrol (gasoline) engine that began production in 2009. The N55 replaced the BMW N54 engine and was introduced in the F07 5 Series Gran Turismo.

The N55 was BMW's first straight-six engine to use a twin-scroll turbocharger. It also won three straight Ward's 10 Best Engines awards in 2011–2013.^[1]

Following the introduction of the BMW B58 engine in 2015, the N55 began to be phased out.^[2]

The BMW S55 engine is a high performance version of the N55 made by BMW M GmbH, which is used by the F80 M3, F82 M4 and F87 M2 Competition/CS.

Design

The main differences between the N55 and its N54 predecessor are the use of a single turbocharger, the addition of Valvetronic and the type of fuel injectors. Whilst the N54 used a twin-turbo arrangement, the newer N55 uses only a single twin scroll turbocharger.^{[3] [4]} Valvetronic (variable valve lift) is claimed to improve throttle response, low-rev torque, exhaust emissions and to reduce fuel consumption by 15%.^{[5] [6] [7]} The direct injection system uses solenoid-type injectors, instead of the piezo-type fuel injectors used by its N54 predecessor. The piezo injectors were more expensive and BMW decided they were not worthwhile outside of Europe, because the potential benefits of lean-burn operation could not be fully realised.^[6]

The exhaust manifold design, called Cylinder-bank Comprehensive Manifold (CCM) by BMW, aims to reduce the pressure fluctuations to reduce throttle lag and exhaust back-pressure.^[8] The twin-scroll turbocharger uses 2 sets of exhaust duct to turn 1 turbine wheel, with cylinders 1–3 and 4–6.^[9] The engine management system is Bosch MEVD 17.2, and compatible fuels are ROZ (RON) 91–98 octane (minimum RON 95 is recommended),^{[10] [11]}

The compression ratio is 10.2:1, the bore is 84mm, the stroke is 89.6mm and the displacement is 29791NaN1, all of which are unchanged from its predecessor, the N54.

Versions

Version	Power	Torque	Redline	Years
N55B30M0	2250NaN0 at 5,700–5,800 rpm	4000NaN0 at 1,200–5,000 rpm	7,000 rpm	2009–2019
N55B30	2350NaN0 at 4,505–6,000 rpm	4500NaN0 at 1,300–4,500 rpm		2011–present
N55B30O0	2400NaN0 at 4,505–6,000 rpm			2014–2016
N55HP	2500NaN0 at 4,505–6,000 rpm			2013–2015
N55B30T0	2650NaN0 at 5,255–6,000 rpm	4650NaN0 at 1,350–5,250 rpm		2015–present
	2720NaN0 at 6,500 rpm	5000NaN0 at 1,450–4750 rpm
Alpina	3010NaN0 at 5,500–6,250 rpm	6000NaN0 at 3,000–4,000 rpm		2013–2017
	3240NaN0 at 5,500–6250 rpm			6600NaN0 at 3,000–4,000 rpm	2017–present
	3320NaN0 at 5,500–6,250 rpm	6800NaN0 at 3,000–4,500 rpm		2018–present

N55B30M0

Applications:

• 2009–2017 F10/F11/F07 535i
• 2010–2013 E90/E91/E92/E93 335i
• 2010–2013 E82/E88 135i
• 2010–2017 F25 X3 xDrive35i
• 2011–2013 E70 X5 xDrive 35i
• 2011–2015 F30/F34/F31 335i
• 2011–2014 E71 X6 xDrive 35i
• 2012–2015 E84 X1 xDrive35i
• 2013–2016 F32/F33/F36 435i
• 2014–2018 F15 X5 xDrive 35i
• 2014–2019 F16 X6 xDrive35i
• 2014–2016 F26 X4 xDrive 35i

N55B30

Applications:

• 2011–2018 F06/F12/F13 640i^[12]
• 2012–2013 E82/E88 135is^[13]
• 2012–2015 F20/F21 M135i^{[14] [15]}
• 2012–2015 F01/F02 740i/Li

N55B30O0

Applications:

• 2013–2016 F22/F23 M235i
• 2015–2016 F20/F21 M135i LCI

N55HP

Applications:

• 2013–2015 F30 ActiveHybrid 3
• 2011–2016 F10 ActiveHybrid 5

N55B30T0

Applications:

• 2016–2018 F87 M2 — 2720NaN0
• 2015–2018 F26 X4 M40i — 2650NaN0

Alpina

Biturbo engine by Alpina based on the N55B30M0. The crankcase is of a different design and specially cast by BMW for Alpina.^[16]

301 kW version

The N55R20A is Alpina's initial version of the N55, producing 3010NaN0. The twin turbocharger system of the N54B30 is used, replacing the twin-scroll charging system originally applied.

Applications:

• 2013–2017 Alpina F30 B3 Bi-Turbo^[17]
• 2013–2017 Alpina F33/F34 B4 Bi-Turbo

324 kW version

Applications:

• 2017–present Alpina F30/F31 B3 S Bi-Turbo
• 2017–present Alpina F32/F33 B4 S Bi-Turbo

332 kW version

Application:

• 2018–present Alpina F32/F33 B4 S Bi-Turbo Edition 99

S55 engine

The S55 engine is the high-performance engine developed from the N55 by BMW M. It was introduced in the F80 M3 and F82 M4 replacing the BMW S65 naturally aspirated V8 engine used in the previous generation M3 and was later used in the F87 M2 Competition/CS.

Differences compared with the N55 include a closed-deck engine block, lightweight crankshaft, different crankshaft bearings, strengthened pistons/rods, different springs/valve material, twin turbos, twin fuel pumps, active exhaust, revised cooling system and intercoolers.^{[18] [19]}

2050NaN0 – 2680NaN0 version

Applications:

• 2020–2021 F87 M2 CS Racing^[20]

3020NaN0, 550Nm version

Applications:

• 2019–2021 F87 M2 Competition^[21]

3170NaN0 version

Applications:

• 2014–2018 F80 M3^[22]
• 2014–2020 F82/F83 M4

3310NaN0 version

Applications:

• 2016–2018 F80 M3 with Competition package^[23]
• 2016–2020 F82/F83 M4 with Competition package^[24]
• 2020–2021 F87 M2 CS^[25]

3380NaN0 version

Applications:

• 2018 F80 M3 CS
• 2017–2020 F82 M4 CS

3680NaN0 version

This version produces 3680NaN0 and 6000NaN0,^[26] due to the use of a water injection system. Three water injectors are used to lower the temperature of the air in the intake manifold, allowing the boost pressure to be increased from 17.2psi to 21.6psi.^{[27] [28]}

Applications:

• 2015–2016 F82 M4 GTS
• 2017 F82 M4 DTM Champion Edition^[29]

See also

• List of BMW engines

Notes and References

1. Web site: Ward's 10 Best Engines Winners, 1995–2012. wardsintelligence.informa.com. 5 January 2012. 21 December 2021. https://web.archive.org/web/20120311095404/http://wardsauto.com/datasheet/wards-10-best-engines-winners-1995-2012. 11 March 2012. dead.
2. Web site: BMW University Technical Training- B58 Engine. Bimmerfile.com.
3. Web site: Ryan ZumMallen . Pop The Hood: Inside the Innovative N55 Engine in the BMW 335i . Automedia.com . 2012-08-13 . 2012-08-04 . https://web.archive.org/web/20120804203223/http://www.automedia.com/Blog/Post/Pop-The-Hood-Inside-the-Innovative-N55-Engine-in-the-BMW-335i.aspx . dead .
4. Web site: BMW unveils single turbo N55 six-cylinder engine for new 5-series GT . Motorauthority.com. 26 May 2009 .
5. Web site: BMW N54 and N55 Six Cylinder Turbocharged Engines. Unixnerd.demon.co.uk. 20 December 2017. 20 February 2020. https://web.archive.org/web/20200220005506/http://www.unixnerd.demon.co.uk/n54.html. dead.
6. Web site: BMW's Newest I-6 Better, Not Bigger . Wardsauto.com.
7. Web site: 2011 BMW 335i Sedan . Caranddriver.com.
8. Web site: The NEW ///M Motor in Depth . Bimmerfile.com. May 2009 .
9. Web site: Turbocharging Technology (F30) . Kneb.net . dead . https://web.archive.org/web/20150615011535/http://www.kneb.net/bmw/F30/08_Turbocharging%20Technology.pdf . 2015-06-15 .
10. Web site: F30 powertrain . bmwuniversity.com . dead . https://web.archive.org/web/20140603225157/http://prodcds.bmwuniversity.com/library/bmw/Technician/Technical%20Training%202011/ST1113%20F30%20Complete%20Vehicle/02_F30%20Powertrain.pdf . 2014-06-03 .
11. Web site: Engine Electronics IPO's (F01-02) . Kneb.net . dead . https://web.archive.org/web/20140603225215/http://www.kneb.net/bmw/F01-02/02_Engine%20Electronics%20IPOs.pdf . 2014-06-03 .
12. Web site: Six-Cylinder 2012 BMW 640i Coupe Priced from $74,475, Convertible from $81,975 . Blog.caranddriver.com . 2011-09-24 . 2011-09-25 . https://web.archive.org/web/20110925004150/http://blog.caranddriver.com/six-cylinder-2012-bmw-640i-coupe-priced-from-74475-convertible-from-81975/ . dead .
13. Web site: BMW 135is Coupe – Model Overview. Bmwusa.com.
14. Web site: 2012 BMW M135i . Autoblog.com. 24 July 2012 .
15. Web site: BMW's M135i is much better than it looks . Ausmotive.com.
16. News: The Alpina philosophy – motoring.com.au. Gratton. Ken. 2016-12-23. motoring.com.au. en-US. 2016-12-24.
17. Web site: Road Vehicle Descriptor (RVD1). rvcs-prodweb.dot.gov.au. 2016-11-24. 2016-11-25. https://web.archive.org/web/20161125045214/http://rvcs-prodweb.dot.gov.au/perl/47254_1126450_RVD_20Apr2015083100.cmd. dead.
18. Web site: F80 M3 / F82 M4 Complete Technical Docs (With S55 Engine Guide). Bimmerpost.com.
19. Web site: Meet The New S55 Engine. Bmwblog.com. 25 September 2013 .
20. News: BMW M2 CS Racing makes its North American debut. autodevot.com. 2020-02-02. en.
21. News: BMW M2 Competition specs leaked. MotorMag.com.au. 2018-04-10. en.
22. Web site: 2013 BMW M3 F80 specifications. Carfolio.com. 21 July 2017.
23. Web site: BMW M3 Sedan – BMW Australia. Bmw.com.au. 30 May 2018. 2 May 2018. https://web.archive.org/web/20180502230611/https://www.bmw.com.au/bmw-cars/m-series/2017-m3-sedan. dead.
24. Web site: BMW M4 Coupé – BMW Australia. Bmw.com.au. 30 May 2018. 2 May 2018. https://web.archive.org/web/20180502213719/https://www.bmw.com.au/bmw-cars/m-series/2017-m4-coupe. dead.
25. Web site: 444-Horsepower M2 CS Can Be Had With 3 Pedals. 2019-11-06. BimmerLife. en-US. 2019-12-31.
26. Web site: 2015 BMW M4 GTS specifications. Carfolio.com. 30 December 2017.
27. Web site: First Drive Review – 2016 BMW M4 GTS. Caranddriver.com. 30 December 2017.
28. Web site: The 2016 BMW M4 GTS is a street-legal water-injected track monster, and it's coming to the US. Autoweek.com. 30 December 2017.
29. Web site: BMW M4 DTM Champion Edition marking Marco Wittmann's 2016 DTM championship title. . BMW PressClub Global . 31 October 2019.