Mercedes-Benz has revealed a BMW-rivalling 3.0-litre in-line turbo six-cylinder with an Audi-challenging electric compressor to eliminate lag and make beyond 300kW/500Nm.

The potent straight six is part of a new modular engine family with 500cc capacity per cylinder, which will spawn a 200kW 2.0-litre twin-scroll turbo four likely for the next A250, and a 350kW/700Nm 4.0-litre twin-turbo V8 for larger sedans.

Mercedes-Benz engine

A similar system is used in the Audi SQ7, but it teams an electric turbo with a 4.0-litre V8 engine to make 320kW and 900Nm.

Tuning Mercedes-Benz engine output

The in-line replacement will be more powerful and potentially torquier, and along with the new twin-turbo V8 that gets cylinder deactivation technology to save fuel, will debut in a facelifted S-Class limousine range later this year.

Mercedes-Benz S-class driving

But it’s the 240kW/450Nm BMW 340i that Benz will target the new engine at, in addition to the Audi S4 makes 260kW/500Nm from its 3.0-litre turbo V6. And with beyond 300kW and over 500Nm, the new C-Class, E-Class and S-Class straight six should really make a mark.