BMW N55 Head Gasket Keychain - M135i M235i M2 Stainless Memento

This stainless-steel head gasket keychain celebrates the BMW N55, BMW’s turbocharged 3.0-litre inline-six petrol-engine family. Introduced in 2009, the N55 replaced the earlier twin-turbo N54 in many BMW models and became BMW’s first turbocharged engine to combine Valvetronic variable valve lift with direct injection and a single twin-scroll turbocharger.

Engine Identity

Manufacturer: BMW AG.
Engine family: N55.
Common engine codes: N55B30M0, N55B30O0 and N55B30T0; exact engine code, output and emissions specification vary by model, market and production year.
Configuration: Front-mounted, longitudinal or transverse turbocharged inline-six petrol engine.
Cylinder count: 6
Displacement: 2,979 cc / 3.0 litres.
Production period: 2009–2017 for the core N55 family, with individual vehicle applications continuing beyond this period in some markets.
Valvetrain: DOHC, four valves per cylinder and 24 valves total, using Double VANOS variable cam timing and Valvetronic variable valve lift.
Fuel system: High Precision direct petrol injection, quoted at 200 bar in BMW technical descriptions.
Induction: A single twin-scroll turbocharger.

The N55 uses an aluminium crankcase with directly coated cylinder bores, rather than iron cylinder liners. It has an 84.0 mm bore and 89.6 mm stroke, giving a 2,979 cc capacity and a 10.2:1 compression ratio.

Vehicle Compatibility Matrix

The N55 appeared across a broad BMW range. The matrix below lists principal applications; engine code, power output and market availability must be checked against the vehicle VIN or engine label.

N55 variant	Vehicle	Chassis	Model years	Typical factory output
N55B30M0	BMW 535i Gran Turismo	F07	2009–2017	306 PS / 400 Nm in launch specification.
N55B30M0	BMW 335i / 335i xDrive	E90/E91/E92/E93; F30/F31/F34	2010–2015	Typically 306 PS / 400 Nm.
N55B30M0	BMW 535i / 535i xDrive	F10/F11	2010–2017	Typically 306 PS / 400 Nm.
N55B30O0	BMW 135i / 135is and M135i	E82/E88; F20/F21	2010–2016	Approximately 320–326 PS and 450 Nm.
N55B30O0	BMW 435i / 435i xDrive	F32/F33/F36	2013–2016	306 PS / 400 Nm in common European specification.
N55B30O0	BMW 640i / 640i Gran Coupé	F12/F13/F06	2011–2018	Approximately 320–326 PS and 450 Nm.
N55B30O0	BMW X3 xDrive35i / X4 xDrive35i	F25/F26	2011–2017	Approximately 306–313 PS, market dependent.
N55B30T0	BMW M2	F87	2016–2018	370 PS / 465 Nm, with 500 Nm temporary overboost.
N55B30T0	BMW M235i / M235i xDrive	F22/F23	2014–2016	326 PS / 450 Nm.
N55B30T0	BMW X4 M40i	F26	2016–2018	360 PS / 465 Nm.

The N55 family also appeared in BMW 1 Series, 3 Series, 4 Series, 5 Series, 6 Series and X5 applications, with engine availability changing by market. The N55B30T0 in the F87 M2 is a higher-output M Performance derivative and should not be treated as identical to a standard 306 PS N55B30M0.

Why This Engine Matters

The N55 marked a shift in BMW’s turbocharged six-cylinder strategy by replacing the N54’s two small turbochargers with one twin-scroll turbocharger. It retained strong low-rpm torque while adding Valvetronic variable valve lift, direct injection and Double VANOS in a more compact turbocharged package.

The standard engine produced 306 PS and 400 Nm, available from 1,200 to 5,000 rpm in the original 535i GT calibration. Higher-output variants developed up to 370 PS in the F87 BMW M2, making the N55 significant to both mainstream BMW six-cylinder cars and the early M2 story.

Technical Specifications

Specification	BMW N55B30 reference architecture
Capacity	2,979 cc / 3.0 litres.
Configuration	Turbocharged inline-six petrol engine.
Cylinder head	DOHC, four valves per cylinder; 24 valves total.
Bore x stroke	84.0 x 89.6 mm.
Compression ratio	10.2:1
Block	Aluminium crankcase with directly coated cylinder bores.
Fuel system	High Precision direct injection, 200 bar.
Turbocharger	Single twin-scroll turbocharger.
Valve technology	Double VANOS and Valvetronic.
Timing drive	Timing chain.
Example standard output	306 PS / 225 kW at 5,800 rpm; 400 Nm from 1,200–5,000 rpm.
Example higher-output output	320–326 PS and 450 Nm for N55B30O0 applications.
F87 M2 output	370 PS / 272 kW at 6,500 rpm; 465 Nm from 1,400–5,560 rpm, with 500 Nm temporary overboost.
Maximum engine speed	Approximately 7,000 rpm in standard N55B30 applications.

N55 output varies considerably between calibration levels, and a 306 PS 535i, 326 PS M235i and 370 PS M2 should not be described as equivalent engines for service-parts purposes. Use the engine code and VIN to identify the correct parts for a specific vehicle.

Product Details

Stainless-steel head gasket keychain inspired by the BMW N55 3.0-litre turbocharged inline-six cylinder-head gasket profile.
Designed for owners and enthusiasts of N55-powered BMW 135i, 335i, 435i, 535i, 640i, M135i, M235i and F87 M2 models.
Finished using our three-stage vibratory polishing process for a smooth, durable metal finish.
Supplied on a plywood display card for gifting, collecting or display.
A compact tribute to BMW’s single-twin-scroll-turbo, direct-injected six-cylinder era.

FAQ

What is the BMW N55 engine?

The BMW N55 is a 2,979 cc turbocharged inline-six petrol-engine family that combines direct injection, Double VANOS, Valvetronic and a single twin-scroll turbocharger.

Which BMW models use the N55?

N55 engines were used in numerous BMW 1 Series, 3 Series, 4 Series, 5 Series, 6 Series and X-model applications, including the 135i, 335i, 435i, 535i, 640i, M135i, M235i, X3 xDrive35i and F87 M2.

Is the N55 the same as the N54?

No. Both are turbocharged 3.0-litre BMW inline-sixes, but the N54 uses two turbochargers while the N55 uses one twin-scroll turbocharger and adds Valvetronic variable valve lift.

Is this a functional replacement head gasket?

No. This is a decorative stainless-steel keychain inspired by the BMW N55 head-gasket shape; it is not an engine-service component.

N55 – BMW M135i, M235i, M2 & 335i Head Gasket Keychain