Mercedes-AMG finally announces the official specs for its new 2.0-litre turbocharged four-cylinder engine that goes under the internal designation M139. In the higher-spec S trim, the mill offers 416 bhp and beats the previous-gen A45 with 375 bhp to take the title as world's most powerful factory-offered four-cylinder engine ever available in a production vehicle. If we want to split some very thin hairs, the Mitsubishi Lancer Evolution FX-440 MR made 440 bhp from its 2.0-litre four-cylinder, but production amounted to just 40 units exclusively for the UK.

Specifically, the S version of the M139 makes 416 bhp at 6,750 rpm and 369 pound-feet of torque between 5,000 and 5,250 revs. The redline hits at 7,200 rpm.

There's also a standard variant of the M139 that produces 382 bhp at 6,500 rpm and 354 lb-ft between 4,750 and 5,000 rpm. The redline is the same 7,200 revs.

Gallery: Mercedes-AMG M139 four-cylinder engine

Both versions of the M139 use a twin-scroll turbocharger. The S variant can produce up to 30.5 psi (2.1 bar) of boost, but the standard model goes to 27.6 psi (1.9 bar).

To get into the nitty-gritty details, The M139 weighs 354 pounds (160.5 kilograms). The four cylinders each have a bore of 83 millimetres (3.268 inches) and stroke of 92 mm (3.622 inches). The mill features both direct injection and indirect injection through the intake manifold. There are two overhead camshafts operating on 16 valves, and the drivetrain is capable of tweaking the valve operation on both sides, in addition to Camtronic valve opening adjustment for the exhaust side.

The horsepower specs for the M139 already leaked out from a German insurance site. This announcement finally makes the numbers official, in addition to providing a bevy of other technical details.

The M139 engine will be available in a variety of models in the near future. The first of them to debut should be the A45 in the very near future. This hot hatch will also be found in the CLA 45 saloon. Spy shots indicate that the boxy GLB-Class crossover gets this powerplant, too.

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2,0-Liter-Vierzylinder-Turbomotor M 139


1.991 cm3

Bohrung x Hub

83,0 x 92,0 mm


310 kW (421 PS) bei 6.750/min (S-Modell)

285 kW (387 PS) bei 6.500/min (Basismodell)

Max. Drehmoment

500 Nm bei 5.000-5.250/min (S-Modell)

480 Nm bei 4.750-5.000/min (Basismodell)

Max. Drehzahl





Ein Twin-Scroll-Abgasturbolader mit wälzgelagertem Verdichter- und Turbinenrad

Max. Ladedruck

2,1 bar (S-Modell)

1,9 bar (Basismodell)


Kombinierte Direkt- und Saugrohreinspritzung.

1.) Mehrfach-Direkteinspritzung der dritten Generation. Schnelle und präzise arbeitende Piezo-Injektoren spritzen den Kraftstoff mit hohem Druck in die Brennräume

2.) Zusätzlich Saugrohr-Kanaleinspritzung mit Magnetventilen


Zwei obenliegenden Nockenwellen, 16 Ventile, Verstellung der Einlass- und der Auslassnockenwelle, Ventilöffnungsdauer-Verstellung CAMTRONIC für die Auslassnockenwelle

Max. Luftmassendurchsatz

1.200 kg/h (S-Modell)

1.100 kg/h (Basismodell)

Motorgewicht (GZ)

160,5 kg