THE DECISION to abandon the V6 after 20 years is just part of a major new engine strategy from Mercedes-Benz.

Joining the new in-line six cylinder petrol and diesel engines, is the new four-cylinder diesel unveiled in the latest Mercedes-Benz E-Class and a new 4.0-litre petrol V8 as part of the modular program.

The new engines are intended only for longitudinal applications for every model based on the rear or all-wheel drive C-, E- and S-Class and their sister crossover models.

The petrol 2999cc in-line six gets a bore 83.00mm and stroke of 92.0mm, while the diesel is 82.0mm by 92.3mm, dimensions that are shared with the four-cylinder diesel.

The 4.0-litre V8 shares the same 82.0 x 92.0mm as the petrol six.

Fours and sixes, with parts variation between petrol and diesels, share the same piston, crankshaft design, cylinder head design, injection and combustion chamber design.

The in-line four and sixes are noticeably narrower than the V6 with the so-called “new exhaust after treatment” that locates components like the catalytic convertor effectively in the exhaust manifold.

Henceforth, the in-line four and in-line six engines will be manufactured on the same lines.

BMW, of course, does a similar thing, and the Bavarians have expanded their approach to three-cylinder engines, in which Mercedes claims no interest.

In some markets Mercedes eventually plans to sell four-cylinder versions of the new S-class using the new engines.

AMG is also known to be developing a new version of the in-line six for the C-Class AMG models.