2015 Geneva Motor Show: Inline six back for Mercedes

Classic straight-six engine set to return in next-generation Mercedes E-Class

MERCEDES-Benz is set to reintroduce inline six-cylinder engines as part of a simplified modular engine strategy.

The head of Mercedes-Benz research and development, Thomas Weber, said the new engine family would reduce costs and production complexity while reintroducing a long-running engine configuration to the German brand.

Weber stopped short of confirming the new engine, but went into detail justifying such a move and why it would make sense financially and from a historical perspective.

He even suggested it could appear in the next-generation E-Class, which is due within two years.

“Of course we are doing something to prepare our engine line-up for the future,” Weber said at the 2015 Geneva motor show.

“We are a company coming from the inline six (cylinder). That was a successful factor for decades in the past.”

Weber said the shift to an inline six-cylinder would allow it to use the basic architecture of the four-cylinder engine – in a similar way that two four-cylinders were used to create the latest AMG V8.

“Looking forward, it’s now clear we are back to the situation that, should we stay with a V6 family only or is there opportunity to do something in combination four and six?” he said.

The creation of an inline six-cylinder would also allow Mercedes-Benz to easily create a V12 using the same architecture across the engine family of four, six and eight-cylinder engines.

Weber confirmed there would be two basic engine families – “big and small displacement; 2.0-litre and above for big ones (and) 1.5, 1.4 for the small ones”.

“Such a strategy is perfect for our brand.

“When we have such a small engine … the step to three-cylinder you are playing a different league … for Smart and [small Mercedes-Benz models].”

Inline six-cylinder engines have been a dying breed, with carmakers switching to more compact V6 configurations.

Only BMW, Ford and Volvo still produce an inline-six. But Volvo is gradually replacing its engine with four-cylinder units, while Ford’s remaining inline six – the Falcon – will be killed off by October 2016.

BMW has stuck with what it considers a superior configuration.