| Mercedes-Benz M139 | |
| Manufacturer: | Mercedes-AMG |
| Production: | 2019-present |
| Predecessor: | Mercedes-Benz M133 engine |
| Configuration: | Inline-four engine |
| Displacement: | 1991cc |
| Bore: | 83mm |
| Stroke: | 92mm |
| Block: | Aluminium alloy |
| Head: | Aluminium alloy |
| Valvetrain: | DOHC |
| Compression: | 9.0:1 |
| Turbocharger: | One twin-scroll, electrically assisted |
| Fuelsystem: | Combined Direct and Port Fuel Injection |
| Fueltype: | Gasoline |
| Power: | 2850NaN0 base version3100NaN0 S-model |
| Torque: | 4800NaN0 (base version)5000NaN0 (S-model) |
| Weight: | 160.5kg (353.8lb) |
The M139 is a turbocharged inline-four engine produced by Mercedes-Benz. It is the successor of the M133 engine. It is also the first four-cylinder engine by AMG to be specified with two outputs, to be assembled by hand using "one man, one engine" philosophy, and to be equipped with combined port and direct fuel injection system. At 3100NaN0 on its introduction, M139 was the world's most powerful four-cylinder engine in serial production with specific output of 208 hp per litre or 104 hp per cylinder.[1] [2] The current top trim of the M139 produces 3500NaN0, giving it a specific output of 175kW per litre or 87.5kW per cylinder, making it the current most powerful four-cylinder engine in serial production.
The M139 engine is based on the current M260 engine, which is an upgraded version of the outgoing M270, sharing the same bore and stroke dimension as well as the block. Unlike the normal M260, the AMG engineers rotated the engine block 180 degrees so that the intake system is in the front of the engine, while the turbochargers and exhaust headers are situated between the engine and firewall.[3] The rotation optimises the engine air flow for higher performance and with shorter distance and fewer diversions. This also "allows the flattest possible and aerodynamically advantageous front section design."[4] The exhaust valves in M139 engine are bigger than ones in M133 engines for higher flow. The compression ratio is raised to 9.0:1 for M139 from 8.6:1 for M133. The two-stage fuel injection system, a first in AMG four-cylinder engine, has the piezo injectors delivering the fuel directly into the combustion chambers as first stage and solenoid valves in the manifolds as second stage for increased specific output.
An electrically assisted turbocharger system by Garrett Motion is used.[5]
The M139 engine has two specific outputs: 2850NaN0 and 4800NaN0 for the base version; and 3100NaN0 and 5000NaN0 for the S-model.
| Engine | Power | Torque | Years |
|---|---|---|---|
| M139 | 2850NaN0 at 6,500 rpm | 4800NaN0 at 4,750-5,000 rpm | 2019- |
| 3000NaN0 | 5000NaN0 | 2022- | |
| 3100NaN0 at 6,750 rpm | 5000NaN0 at 5,000-5,250 rpm | 2019- | |
| M139I | 3500NaN0 at 6,750 rpm | 5450NaN0 at 5,250-5,500 rpm | 2023- |