The Mercedes CLS is being fine-tuned for production ahead of its launch at next year’s Paris motor show.

It will be the firm’s first model to get a new range of turbocharged, direct injection petrol engines. All of these units will be turbocharged when the car goes on sale soon after its unveiling.

Mercedes isn’t moving too far from the four-door coupe theme that it pioneered. Although the car will be recognisably a CLS, the styling is all new, with a significantly different rear end with new rear lights and a very different boot lid.

The frameless doors remain and the rear arches mimic the distinctive shape of the E-class coupe.

The new engine line up starts with a 3.0-litre V6 with 252 and 306bhp. Two big petrol twin-turbo V8s will be available, a 4.6 with 435bhp and a 5.5 with 544bhp.

The diesels include the new 2.1-litre four-cylinder with 204bhp and an upgraded 3.0-litre V6 with 231bhp.

Underneath the CLS is based on the new E-class, but doesn’t get an extended wheelbase; at 2874mm it’s the same as the new E-class and the current CLS. The car will be 4925mm long.

Inside the car will retain its unique dashboard and a four-seat layout, using switchgear and elements from the new E-class.

Pics: Carpix

Twitter - follow autocar.co.ukSee all the latest Mercedes reviews, news and video