BMW N55

BMW N55 engine
Overview
Manufacturer BMW, Bayerische Motoren Werke AG
Production 2009–Present
Combustion chamber
Configuration Straight-6
Chronology
Predecessor BMW N54

The BMW N55 is a turbocharged direct injection straight-6 DOHC piston engine which has been in production since 2009, being initially launched in the BMW 535i Gran Turismo (F07).[1]

The N55 generally replaced the N54 in most applications, especially after the release of the N55HP in 2011 for 2012 models, but high-output versions of the N54 remain in production.[2][3]

While having the same displacement and peak power output as the N54, the N55 is 15% more fuel efficient, has lower emissions, less turbo lag and better low-rev torque.[4][5]

N55

Design

While its N54 predecessor uses parallel twin-turbochargers, the N55 uses a single twin scroll turbocharger.[6][7] BMW has used the term "TwinPower Turbo" to describe both twin-turbo and (single turbocharger) twin-scroll systems.

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 N55 also adds Valvetronic variable valve lift, a feature not available in the N54.[4]

The N54's gasoline direct injection system uses piezo injectors, also used in the naturally-aspirated N53 (mostly European markets only), the N55's direct injection uses Bosch solenoid-type injectors. The piezo injectors were more expensive and BMW decided they were not worthwhile in North America, in contrast to Europe which they could perform lean burn to reach their full potential.[4]

The engine includes BOSCH MEVD 17.2 engine management, and supports ROZ(RON) 91-98 octane fuel types (recommended RON 95),[9][10] Valvetronic III (variable valve lift control) with double VANOS, direct injection and turbocharging. Turbocharging uses 2 sets of exhaust duct to turn 1 turbine wheel, with cylinders 1-3 and 4-6 combined to form 2 exhaust channels.[11]

The N55 is mated to ZF's 8-speed automatic transmission in most applications such as the 2011 535i and 2013 BMW 740i,[12] and a 6-speed manual is usually available for sedans (excluding the 7-Series, and dropped for the 5 and 6 series for 2015), but not crossovers such as the X3, X5 and X6. The N55 engines in the 2011 BMW 135i and 2013 BMW 135is are mated to Getrag 7-speed Dual-clutch transmission or a 6-speed manual transmission.[13][14]

Models

Engine codeDisplacement (bore x stroke)PowerTorqueRedline (rpm)Compression ratio (:1)Year
N55B30M02,979 cc (182 cu in) (84.0 mm × 89.6 mm (3.31 in × 3.53 in)) 225 kW (306 PS; 302 hp)@5800-6000400 N·m (295 lb·ft)@1200-5000700010.22009-
N552,979 cc (182 cu in) (84.0 mm × 89.6 mm (3.31 in × 3.53 in))235 kW (320 PS; 315 hp)@5800-6000450 N·m (332 lb·ft)@1300-4500700010.22010-
N55B30O02,979 cc (182 cu in) (84.0 mm × 89.6 mm (3.31 in × 3.53 in))240 kW (326 PS; 322 hp)@5800-6000450 N·m (332 lb·ft)@1300-4500700010.22011-
N55HP2,979 cc (182 cu in) (84.0 mm × 89.6 mm (3.31 in × 3.53 in))250 kW (340 PS; 335 hp)@5800-6000450 N·m (332 lb·ft)@1300-4500700010.2 Overboost @ 500 N.m2013-

Applications

N55B30M0 (225kW)

N55 (235 kW)

N55B30O0 (240kW)

N55HP (250 kW)

See also

References

  1. ↑ Tan, Paul. "The New BMW 5-Series Gran Turismo". Paultan.org. Retrieved 2011-09-23.
  2. ↑ http://www.bmwblog.com/2013/04/22/2014-bmw-z4-sdrive35is-first-drive-review-by-autocar. Retrieved 2014-01-27. Missing or empty |title= (help)
  3. ↑ "2011 BMW 740 Reviews, Expert Car Reviews on AOL Autos". Autos.aol.com. Retrieved 2012-10-06.
  4. ↑ 4.0 4.1 4.2 Sousanis, John (2011-08-01). "BMW's Newest I-6 Better, Not Bigger | News & Analysis content from". WardsAuto. Retrieved 2012-10-06.
  5. ↑ 5.0 5.1 "2011 BMW 335i Sedan - First Drive Review - Auto Reviews". Car and Driver. Retrieved 2011-09-23.
  6. ↑ Ryan ZumMallen. "Pop The Hood: Inside the Innovative N55 Engine in the BMW 335i". Automedia.com. Retrieved 2012-10-06.
  7. ↑ "BMW unveils single turbo N55 six-cylinder engine for new 5-series GT". Motorauthority.com. 2009-05-26. Retrieved 2012-10-06.
  8. ↑ "Archive » Exclusive: The NEW ///M Motor in Depth". BimmerFile. 2009-05-23. Retrieved 2012-10-06.
  9. ↑ F30 Powertrain
  10. ↑ Engine Electronics IPO's (F01-02)
  11. ↑ Turbocharging Technology (F30)
  12. ↑ "Six-Cylinder Midsize Luxury Sedan Comparison - Audi A6, BMW 535i, Lexus GS 350, Infiniti M37". Motor Trend. Retrieved 2012-10-06.
  13. ↑ "World Premiere: 2013 BMW 135is Coupe and Convertible 320 HP From $44,145". Bmwblog.com. 2012-05-15. Retrieved 2012-10-06.
  14. ↑ You must be logged in to post (2010-06-08). "2011 BMW 135i DCT - BMW Luxury Coupe Review - Automobile Magazine". Automobilemag.com. Retrieved 2012-10-06.
  15. ↑ "BMW Heaven Specification Database | Engine specifications for N55 engines". Bmwheaven.com. Retrieved 2012-10-06.
  16. ↑ You must be logged in to post (2010-09-10). "BMW 335i and 335is - Dyno Test - Automobile Magazine". Automobilemag.com. Retrieved 2012-10-06.
  17. ↑ "Six-Cylinder 2012 BMW 640i Coupe Priced from $74,475, Convertible from $81,975". Blog.caranddriver.com. 2011-09-21. Retrieved 2012-04-23.
  18. ↑ Matt Davis RSS feed. "2012 BMW M135i". Autoblog.com. Retrieved 2012-10-06.
  19. ↑ "BMW’s M135i is much better than it looks". AUSmotive.com. Retrieved 2012-10-06.
  20. ↑ BMW North America. "BMW 135is Coupe - Model Overview - BMW North America". bmwusa.com. Retrieved 2012-10-06.

External links