Mercedes-AMG planning 350kW inline six

MERCEDES-BENZ’S all-new inline six-cylinder petrol engine that will make its Australian debut in the facelifted S-Class later this year is set spawn a mad AMG version for the E-Class Coupe.

Company insiders say the new model – apparently dubbed E50 – will churn out 350kW of power, which is a healthy 55kW more than the current most powerful V6 in the German’s company’s range, the recently launched 295kW AMG E43.

Even in its standard form, the turbocharged 3.0-litre straight six will outperform the current AMG-fettled six, generating 304kW of power and 500Nm of torque.

Although AMG has responsibility for developing V8 and V12 engines for Mercedes, the new six – codenamed 256 – is being developed by Mercedes powertrain engineers.

However, AMG then gets a chance to add some zip in engines for its increasingly important ‘43’ six-cylinder sports models that are more fuel-efficient and cheaper than the V8s and V12s that have been AMG’s bread and butter for years.

The new inline six represents a back-to-the-future move by Mercedes-Benz which dumped its previous generation straight sixes in favour of V6s for packaging reasons some years ago.

Apart from having NVH (noise, vibration and harshness) advantages over a V6, the main reason for the switch back to inline engines is to allow all of its petrol engines to be modular.

Apart from the new six, Mercedes-Benz is also working on a new 1.5-litre three-cylinder and 2.0-litre four-cylinder engines that all use common parts such as pistons, conrods and valves.

The modular engine program also extends to diesels, with the aluminium-block 2.0-litre unit that debuted in the new E220 to be joined by a six that uses many of the same components.

All Mercedes-Benz petrol and diesel engines are now turbocharged, and while research apparently continues into naturally aspirated engines at Mercedes, engineers say the fuel-saving and torque-creating advantages of blown engines are so superior that there are no plans to return to naturally aspirated units.