A fresh report out of Germany suggests Mercedes-AMG plans to fit its new electric exhaust gas turbocharger to the M139 four-cylinder engine.

Earlier in June 2020, the Affalterbach-based division announced it was “working intensively on innovative technologies which will take performance to a new level”, confirming its “next vehicle generation will see the deployment of the electric exhaust gas turbocharger”.

And now the studious folks over at mbpassionblog have pointed out that the part number of the component detailed in an official image starts with the numbers “139”. In addition, another photograph clearly shows the e-turbo fitted to a four-pot block.

Mercedes-AMG e-turbo on M139 engine

The turbocharged 2,0-litre M139 engine is, of course, employed by the A45 S, CLA45 S and GLA45 S, where it delivers a hearty 310 kW.

This latest discovery by mbpassionblog lends further substance to earlier reports the next-generation C63 will switch to a hybrid four-cylinder powertrain using the M139 unit as a base, fitted with the aforementioned e-turbo.

The turbocharging system in question features a slim electric motor (measuring about four centimetres) integrated directly on the charger shaft between the turbine wheel on the exhaust side and the compressor wheel on the fresh air side.

The electronically controlled electric motor drives the compressor wheel before this accepts the exhaust gas flow, “significantly” improving immediate response from idle speed and across the entire rev range. Mercedes-AMG says turbo lag is thus “eliminated” by the electric motor.

The turbocharger can spin at speeds of up to 170 000 r/min and can be operated via a 48 V on-board electrical system. Interestingly, the turbocharger, electric motor and power electronics are connected to the combustion engine’s cooling circuit to create an “optimum temperature environment” at all times.