SWISH, suave and sophisticated were the standards set by Mercedes when it created the CLS super coupe.

With four doors, four seats and the sleekest of bodies, the CLS carved out a new niche for the fashion-conscious.

Here was a car whose success was driven by emotion and desire - not just raw performance and reputation.

Six years on and with 17,000 sold in Britain, Mercedes is setting out to play with a few more heart strings by introducing a new CLS.

But while the new model remains slippery in profile it has grown some chunky bits.

The nose is abrupt, the bonnet chiselled in a mean way and the rear wheel arches have the Ponton treatment of the 1950s as recreated by Mercedes for the current E-Class models.

Like the original, the new car has sharp body cuts curving along the side echoing the sweep of the roof line but now there is a hint of menace.

Shining out from either side of the front grille are LED clusters including the option of the world's first fully automatic headlamp system made up of 71 ultra bright diodes.

Not only do LEDs use less energy than conventional lamps they also last significantly longer and give out illumination more akin to daylight.

Combined with some technological magic in the shape of cameras mounted in the windscreen to gauge ambient light conditions, the CLS headlamps adjust automatically to make sure maximum brightness is delivered as required.

If oncoming traffic is detected or the car enters a lit-up area the beam alters instantly to prevent dazzle.

In pitch darkness the light from the LEDs is noticeably whiter and more natural colour is highlighted.

Approaching drivers will see a white/blue effect and while the lamps are significantly brighter there is no glare.

Not only does the system give superior illumination it also produces a distinctive signature. More LEDs are used in the rear lamps where the effect is equally dramatic.

The groundbreaking set up is one of three new features Mercedes is introducing on the second generation CLS and all are designed to save energy keeping CO2 emissions low.

For the first time on a Mercedes all four doors are made from aluminium to keep weight down while the CLS is also fitted with an electro-mechanical power steering system which uses energy only when the car is manoeuvring.

However, coupled to a rather chunky steering wheel, the feel is rather sterile and takes some getting used to.

The CLS is fitted with the Mercedes 7 G-Tronic auto box with the gear selector mounted on the steering column. Manual changes come from steering wheel paddles and the gearing can be configured for an eco mode which engages a stop/start system.

Compared to the previous CLS Mercedes has chopped exhaust emissions significantly on all four engines which will be available.

Only the new 4.6-litre V8 petrol engine has a CO2 output above the 160g/km threshold which means the bulk of CLS production will be attractive to business users.

When the car goes on sale next March it will be offered with a choice of either a 2.9-litre diesel engine, a 3.4-litre V6 petrol and the V8.

The V6 in the CLS 350 will average a claimed 41.5mpg with the diesel managing 47mpg - an improvement of more than 20 per cent compared to the current engine. Both have emissions of 159g/km.

The V8 in the CLS 500 is Mercedes' new bi-turbo which develops more than 400bhp yet incredibly for an engine which can produce 0 to 60mph in 5.4 seconds it is said to be capable of returning 31.3mpg and 210g/km emissions.

Eventually a 250 CDI model will be added to the line up making the CLS even more eco-friendly with CO2 down to 135g/km and consumption in the region of 55 to the gallon.

On the road the new car is refined, composed and rides beautifully although from a driver's point of view its edge is blunted by the dull steering.

Noise levels are significantly lower than on the previous model - partly down to the repositioning of the door mirrors on the belt-line, a feature which in itself adds to the CLS's looks.

Inside it is absolutely classy with quality wooden trim and plush leather available in a variety of finishes.

Head and leg room is above average, especially in the rear where the two seats are separated by an armrest cum stowage box.

It's top notch luxury and with a good sized 520 litre boot the CLS has all the credentials of a full blown grand tourer.

Instrumentation includes coloured graphics akin to those on the upmarket S-Class while safety systems follow the E-Class range - on which the CLS is based.

In all there are 12 driver safety aids including active lane departure and blind spot alerts which can stop the car drifting into danger. Nine airbags are standard and so is a driver drowsiness monitor.

If ever a car was out to impress on all fronts then it is this but with the launch still more than four months away Mercedes has still to announce prices.

The current range starts just shy of £50,000 and the newcomer is likely to be pitched similarly.