(June 8, 2019) AFFALTERBACH, Germany — With an output of up to 416 horsepower, the completely newly developed Mercedes-AMG 2.0-liter M 139 engine is the world's most powerful turbocharged four-cylinder engine in series production. With this engine, Mercedes-AMG has even exceeded the previously most powerful M 133 engine by 40 horsepower. Maximum torque has also increased from 350 to up to 369 lb-ft.

With an output per liter of up 208 horsepower, the new Mercedes-AMG high-performance turbo engine even ranks ahead of many well-known supercar engines. The new, highly efficient engine is produced on an innovative production line in Affalterbach, on the "One Man, One Engine" principle.

The four-cylinder engine is available in two output versions for the compact models of Mercedes-AMG — with 416 hp for the S-model and 382 hp in the base version. This product policy logic has already proved successful in the V8- powered AMG Performance models, and more closely meets customer wishes.

Apart from its performance figures, the new engine impresses with its immediate response. To this end, the torque curve was carefully balanced with "torque shaping." The peak torque of 369 lb-ft (354 lb-ft for the base version) is available in a range of 5000-5250 rpm (4750-5000 rpm in the base version).

With this configuration, the AMG engineers have achieved a power delivery similar to that of a naturally aspirated engine for an even more emotional  driving experience. The engine developers were also able to realize a dynamically increasing torque curve in the lower engine speed range, thereby improving agility. The increasing torque at higher rpm makes the engine more free revving. Moreover, the high maximum engine speed (up to 7200 rpm) confirms the M 139 as a sports engine.

"We already set the benchmark in the segment with the preceding engine. This fundamentally new four-cylinder presented us with the challenge of doing even better. And we succeeded with a number of sometimes revolutionary solutions," said Tobias Moers, chairman of Mercedes-AMG GmbH.

"With the M 139, we have once again impressively demonstrated the engine expertise of Mercedes-AMG. Not only is the output per liter unrivaled for a turbocharged engine, the high level of efficiency also demonstrates that the internal combustion engine still has further potential."

The new engine is entirely assembled by hand. On the first floor of the AMG engine manufactory in Affalterbach, a newly designed production line was installed in which Mercedes-AMG has brought the "One Man, One Engine" principle to a new level, together with Industry 4.0 methods that incorporate the latest findings in ergonomics, materials handling, quality assurance, sustainability and efficiency.

On the road to implementing Industry 4.0, AMG's hand assembly operation likewise follows the vision of "smart production." This excels with maximum flexibility, and is transparent and highly efficient. It safeguards and improves the quality of the engines and production processes using innovative and digital technologies.

"We have completely revised the principle of 'One Man, One Engine' for assembly of the M 139. The result is an ultra-modern production process that places the focus on people. To achieve this, we created the ideal working conditions in a bright, precisely organized and clean environment for our employees. This provides the best basis for continuing to ensure our high quality level even as the technology becomes more complex," said Emmerich Schiller, COO and member of the Board of Management at Mercedes-AMG GmbH.

The new engine excels with numerous intelligent design features. Compared to the transversely installed M 260 four-cylinder in the "35" models or the preceding M 133 engine, the new Mercedes-AMG M 139 is rotated around its vertical axis by 180 degrees. This means that the turbocharger and the exhaust manifold are positioned at the rear, on the side of the firewall when viewed from behind. The intake system is therefore positioned at the front.

This configuration allows the flattest possible and aerodynamically advantageous front section design. Furthermore, the new arrangement allows for improved air ducts with shorter distances and fewer diversions - both on the intake and exhaust side.

The new twin-scroll turbocharger combines optimum responsiveness at low engine speeds with a high power in the upper rpm range. In addition to this, the turbine housing is divided into two flow passages that run parallel to one another. Together with the divided ducts in the exhaust manifold, this makes it possible to feed the exhaust flow to the turbine separately.

The aim is to prevent the individual cylinders from influencing each other negatively during load cycles, and to improve the gas cycle. The result is higher torque at lower engine speeds, and extremely quick responsiveness.

Furthermore, the shafts of the compressor and turbine have roller bearings for the first time — similar to the top output variant of the AMG 4.0-liter V8 engine in the AMG GT 4-door Coupe. The roller bearings reduce mechanical friction within the turbocharger to a minimum. The charger therefore responds more readily and reaches its maximum speed of up to 169,000 rpm more rapidly.

With a maximum charge pressure of 2.1 bar (1.9 bar in the base version), the 2.0-liter turbo engine is also a top performer in this respect. The electronically controlled wastegate (exhaust relief valve) allows the charge pressure to be controlled even more precisely and flexibly while optimizing responsiveness, especially when accelerating from partial load. Numerous parameters are taken into account in this process.

The main input signals for the wastegate control unit are the charge pressure, throttle flap position and the knocking tendency. The modifying signals include the intake air temperature, engine temperature, engine speed and atmospheric pressure. This also makes temporary boosting of the charge pressure (overboost) possible under acceleration.

Fresh air is used in addition to oil and water to cool the turbocharger. This is directed specifically to the charger from the radiator grille, via the engine cover designed as an air deflector and ducts beneath the hood.

The concept is based on the principles and experience gained with the cooling for the internally mounted turbochargers of the current AMG 4.0-liter V8 engines, starting with the AMG GT in 2014. In addition, the turbine housing incorporates integral insulation.