Mercedes-Benz is applying its thinking from the CLS 'four-door coupé' to create the new A-Class-based CLA.

The CLA, unveiled at the North American Internationial Auto Show in Detroit before a formal public debut in Berlin later this month, will arrive in the UK this summer.

It will use engines already offered in the A-Class range, although its more aerodynamic shape results in improved fuel consumption over the hatchback.

Standard-fit features for the coupé include Attention Assist drowsiness detection and radar-based Collision Prevention Assist with adaptive Brake Assist, which now helps to protect the CLA from collisions from a speed of only 4 mph (previously: higher than 19 mph).

Petrol engines with a displacement of 1.6 and 2.0-litres range from 122 hp in the CLA 180 through to 211 hp in the CLA 250.

Two diesel engines combine dynamic low-end torque with the utmost efficiency: the CLA 200 CDI generates 136 hp, with maximum torque of 221lb-ft (available from the third quarter of 2013).

With a cubic capacity of 2.2 litres, the CLA 220 CDI will offer an output of 170 hp and 258lb-ft of torque, emitting only 109 g CO2 per kilometre.

All the engines feature start/stop as standard. The engines are combined with a six-speed manual transmission or with the 7G-DCT dual clutch automatic transmission.

Expect prices to carry a premium over the equivalent A-Class hatchback.