A cross between a saloon and a coupe, the Mercedes CLS is a highly distinctive proposition, particularly in the company of Mercedes' other four-door offerings. Extremely refined and silky smooth on the road, it also injects a touch of spice with livelier handling than the E-Class which spawned it. Pick the right power option and running costs are more manageable than you'd think.

Conventional wisdom dictates that a coupe has two doors, occasionally three if you count a hatchback rear. Five doors, as boasted by the Mazda RX-8, is pushing things a bit but a quartet of doors is the one attribute that generally precludes entry to the coupe club. Possessed of four doors, you are usually a saloon. Saloons, as we all know, are often a bit staid, driven by middle management and chubby gentlemen the world over. The Mercedes CLS breaks that particular mould. It's breathtakingly striking with flowing coupe-like lines, razor-edged detailing and superb finish. It also has four doors.

Walk around a CLS and - if you're a student of automotive design - you may well feel a gnawing sense of unease. What is it about this car that's so unusual? Yes, a four-door coupe isn't exactly conventional but that isn't it. After a while the realisation dawns that the CLS just plain doesn't seem like a German car. History has taught us that German cars feature clean, pragmatic styling. Even the more extrovert and successful German designs, such as Audi's TT, have a pared-down industrial hygiene about them. The CLS is different insofar that it is unashamedly Baroque, with an attention seeking ostentation suffused throughout it. In short, this car looks American.

Three petrol engines are offered to UK customers. The smallest petrol powerplant is no slouch, being a 292bhp 3.5-litre V6 with piezo-electric direct injection and a spray-guided combustion system. It will get the CLS 350 to 60mph in under 7 seconds and run on to an electronically-limited top speed of 155mph, which means that it's quick enough to keep a BMW 630i honest. If you've got a little more money to throw at a CLS, you may well be tempted by the 388bhp V8-engined CLS 500. Here, you get a couple of extra cylinders offering a fraction better refinement and acceleration, which seems a rather questionable return on what is a significant premium. If you really hanker after a CLS that will lift its skirts and fly, best go for the 514bhp CLS 63 AMG version, a car destined from inception to star in its fair share of gangster rap music videos. The sole diesel option is also the cheapest CLS available. The 224bhp 320 CDI which can hit 60mph in 7s and produces 500Nm feels quicker in real world driving than the 350.

"Neither saloon nor coupe, the Mercedes CLS is a hard car to pin down.."

The 'four-door coupe' billing of the CLS leads us to expect a degree of agility and athleticism beyond that of Mercedes saloons such as the E-Class with which this model shares its basic chassis. It delivers on this to an extent with a greater firmness to the suspension and a tauter feel under cornering loads but the CLS does not sacrifice the ride quality you expect from a four-door Mercedes costing what the CLS costs. The car cossets its driver and passengers while thrilling them with its majestic performance and effortless pace. It doesn't feel particularly like a coupe though and certainly never like anything so uncouth as a sports car.

The CLS almost looks like an evolution of a Los Angeleno low rider from the late fifties and was always destined to be a very hot ticket in America, Mercedes' biggest export market. It's difficult to take in all of the details of the CLS styling at one go. The way the twin swage lines that run along the flanks become the leading edge of the front wheel arch is beautifully resolved and the big L-shaped front lights mark a welcome departure from the gawky 'peanut' headlamps seen on so many contemporary Benzes. Even the door handles look like something from an Art Deco design exhibition. The latest revisions include a revised radiator grille, LED taillights and shapelier mirrors.

Open the door and the surprises continue. The cabin is like no Benz currently offered. A vast plank of wood runs across the dashboard, punctuated by the ventilation controls and a deeply sunken instrument binnacle. Mercedes has kept the cabin fresh by introducing a revised three spoke steering wheel and white-faced instrument dials. Chestnut wood inserts improve the perception of quality and uprated infotainment systems also feature.

The CLS is a four seater with a chunky transmission tunnel dividing the two rear seats. It's easy to forget that there's an additional set of doors at the back, despite Mercedes not adopting Alfa Romeo's clever hidden handle feature. Once opened, taller passengers will have to watch their heads as they climb in, but the legroom isn't bad at all. Compared to its closest rival, BMW's 6 Series, the CLS is a far more practical proposition. Headroom in the back is far from problematic although the high waistline gives a slightly claustrophobic feel. The fact that it's easy to get in and out of the back helps here.

In order to get a handle on the value proposition of the Mercedes CLS, it helps to put it up against some putative rivals. This is, in fact, no easy task, as the CLS is rather out on a limb when it comes to comparisons. Nothing else directly measures up against it, from the BMW 6 Series (not enough doors) to the Audi A8 (too big and bulky). It's not even a particularly valuable exercise to highlight quite how much the CLS costs when compared to an equivalent Mercedes E-Class, as most CLS customers want That Shape and are prepared to pay a significant premium to get it in their garage.

The CLS 350 CGI petrol model is set to become particularly popular in terms of global sales and it's not difficult to see why. A typically specified model will roll out of dealerships in the upper £40k bracket and it offers a lot of car and a whole heap of capability for the money. Think of it as being equivalently priced to, say, a Porsche Cayman S and it looks solid value. The CLS 320 CDI diesel looks a desirable option too, costing similar money to the CLS 350 CGI but lacking that engine's sonorous exhaust note. The 5.5-litre CLS 500 is the preserve of the very wealthy but even the entry-level models don't leave you wanting for much equipment-wise. Climate control, cruise control and part leather trim are standard. The options list holds gems like Keyless Go, a Harman Kardon stereo upgrade, a TV tuner and adaptive Bi-Xenon headlamps.

The diesel is the CLS for those looking to bypass big fuel bills. It manages a very creditable 37.2mpg along with 200g/km CO2 emissions, making it a viable option for company car users. The CLS 350 CGI can achieve 31mpg, so it too is hardly crippling to run in the scheme of things. Costs rise sharply once you progress onto the V8 CLS 500 with 24.4mpg and 275g/km on the cards. Then it's the CLS 63 AMG which returns 19mpg and emits 345g/km of CO2. Greenpeace could hardly be any more offended if you fitted a whaling harpoon gun to the bonnet.

The desirability of the CLS should help it perform strongly on the used market. Comparatively rare cars with evocative styling rarely fall out of bed by the time owners come to sell them on and this shouldn't be an exception. Servicing is not cheap however and the car's coupe status hardly encourages generosity from the insurance industry. Groups range from 18 to 20.

Marketers would dub the Mercedes-Benz CLS a 'high involvement' car. It's a vehicle to which it's possible to form an emotional bond, attracted by its exotic styling and unconventional attitude. This makes it a very special car. When was the last time you could form such a bond with a Mercedes? You could admire a Mercedes, aspire to one, or respect what they did but the three-pointed star was never something that would tug on the heartstrings. The CLS changed that, and this is in part why it's such a culturally disorientating car and one with such a big capacity to surprise.

Neither saloon nor coupe, the Mercedes CLS is a hard car to pin down. Its exotic looks and driving experience suggest it's sportier than a Mercedes four-door should be but its four doors produce practicality and comfort that isn't in keeping with the coupe job description. What's not in doubt is that the CLS remains a ground-breaking car for Mercedes and for the market as a whole.

TOP 4 CLS DEALS

The results below show the top CLS deals on buyacar

	Mercedes-benz CLS CLS 320 CDI 4dr Tip Auto Saloon
	ETR	Mthly £767	Saving £4,248	Price £42,002
	Mercedes-benz CLS CLS 500 4dr Tip Auto Saloon
	ETR	Mthly £949	Saving £5,109	Price £49,936
	Mercedes-benz CLS CLS 350 CGI 4dr Tip Auto Saloon
	ETR	Mthly £787	Saving £4,318	Price £42,632
	Mercedes-benz CLS CLS 63 4dr Tip Auto AMG Saloon
	ETR	Mthly £1,323	Saving £7,109	Price £67,936

typical 11.05% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000