IT has been a stressful day. The sales team has missed its quarterly budgets by so far the WI autumn jumble sale looks like a more profitable exercise. The factory floor has no idea if widget A will actually fit into widget B, especially as all widgets are stuck in Chinese customs and the customer service department quit today because he is off backpacking around South America for a year.

So the last thing needed is a stressful commute home for our tired managing director. In which case, might we recommend he, or she, switches on Distronic Plus, locking on to the car in front, sets the seats to massage, switches the suspension to comfort and turns the opera up on the surround sound stereo.

By the time home is reached, all woes and cares will have slipped away. The new Mercedes-Benz S-class is a vehicle which is primarily designed to insulate you from the world the other side of its rather thick glass, to transport its passengers not only to their destination, but away from the chaos and stress.

It’s something the S-class has been doing better than any other luxury saloon for decades, and its self-styled moniker as the ‘world’s best car’ was certainly justified – once. But in recent years the likes of Audi and Jaguar have given the big Merc a run for its money, although in sales terms only the Jaguar XJ comes close.

Each new version of the S-class has generally heralded a leap forward in what the world can expect from a car in terms of refinement, quality and innovation, but the opportunities to set new jaw-dropping standards is lessening: computer-aided design is levelling the playing field somewhat.

So the S-class is not breaking into uncharted territory, but it is still a very good car, and possibly the best. There are the usual range of vast and powerful engines with the 517bhp 5.5-litre bi-turbo S600, 388bhp 5.5-litre S500, 272bhp 3.5-litre S350 and 235bhp 3.0-litre S320 CDI. And while the other engines are all laudable, it will no doubt be the diesel which attracts the most corporate attention.

According to Dermot Kelly, managing director, Mercedes Car Group, up to 80% of S-class sales will be into the fleet and corporate market, with a third heading to chauffeur fleets.

And of those, more than two-thirds will be the diesel. So it’s a shame there were no diesels on the launch to try.

The diesel also will be on sale a couple of months after the petrol models, in May rather than March.

Volumes for next year should be limited to around 2,500 in the UK, which is a fairly steady level compared with previous years but still some way behind the XJ.

There’s not a vast amount of legroom in the back of the standard wheelbase version, and isn’t much of an improvement over the old model. In fact, the exterior dimensions are not particularly increased, at only 3cm longer and 1.6cm wider.

Certainly if the car is going to be used for chauffeuring the long wheelbase model (with 20cm extra in the wheelbase) at a hefty £4,000 extra is the only option.

Most functions are operated through the Comand controller, which follows (and how often is it that Mercedes-Benz does that with an S-class?) the same principles as the BMW 7-series and Audi A8.

It’s at least as easy and clear to use as the Audi, which obviously makes it considerably better than the BMW.

The screen and the myriad of functions within it are well-designed, graphically impressive and easy to use, and the metallic dial has a precise movement which means you always go to whichever screen you want to.

If the option has been ticked, the various cushions and bolsters of the multi-contour seats can be changed through this, which means you can squeeze the buttocks of the driver from the passenger seat, should the mood take you.

It also comes with some extremely advanced safety systems, such as upgraded Pre-Safe, which prepares for impact if it detects an imminent accident, and Brake Assist Plus which will cut in if the driver isn’t applying enough brake pressure in an emergency.

The out-going S-class has been suffering with more than its fair share of quality issues, with most of them electrical, and too annoyingly difficult to solve for such an expensive car. Engineers are confident that this will not be the case with the new one. The issue with the electronics previously was that problems were occurring almost randomly. So in the development of this car, aircraft-style black boxes were used to run and record the millions of situations the systems could find themselves in, so when there was a problem it could be traced and rectified.

Kelly added that the type of technicians Mercedes-Benz took on was changing as a result, so the firm was now looking for more younger IT-literate types, rather than those just useful with a hammer and screwdriver.

Prices will be around 7% more expensive than equivalent current models, which means an entry-level diesel at nearly £56,000.

Behind the wheel

IT may seem a tough assignment, but Mercedes-Benz chose a route from Milan to St Moritz and back for the launch. But instead of long fast motorways, the journey was a seven-hour blast through winding mountain passes.

In the wobbly old S-class this would have been a test of even the most hardened travelling stomach as it tottered around hairpin after hairpin, but the new car is much more accomplished.

With standard Airmatic air suspension, which can adjust the ride quality from soft to sporty, and adaptive damping, the big S twisted and turned through everything thrown at it with poise as graceful as any large car could.

But super-quiet, smooth cruising is where it excels. It really makes no difference which engine you choose. At motorway speeds there is no noise, just a soft whispering wind and some distant tyre rumble.

Comfort, as you would expect, is superb, and even long trips such as ours are a doddle. It eats up the miles and protects the occupants from all that the outside world has to throw at them.

Mercedes-Benz claims that in tests driving the S-class is more stress-free than the competition, and that drivers had a heart rate of five beats per minute less than in rivals. I can’t say I noticed such a reaction personally, but drive the car over 60,000 miles at an average of 40mph and that’s a saving of 450,000 heart beats, which seems a whole lifetime, and healthily useful for a stressed executive who eats and drinks too much.

What to make of its looks though? There is a school of thought that the big, rounded wheelarches look like a Mondeo, while the boot has all the awkwardness of the Maybach. What cannot be denied is that it has presence, although without the timelessly elegant styling of the out-going car.

The interior is very classy, with top notch materials used throughout – soft leather, a huge block of wood sweeping across the dash and some very moody strip lighting around the waistline.

Driving verdict

THIS could well be the most comfortable car in the world. It also is a vast improvement to drive and oozes quality and has some fantastic kit. But is it the huge leap forward the previous one was? Probably not.

Model:		S320 CDI		S350		S500		S60
Max power (bhp/rpm):		235/N/A		272/N/A		388/N/A		517/N/A
Max torque (lb-ft/rpm):		399/1,600		258/2,400		391/2,80		612/1,900
Max speed (mph):		155*		155*		155*		155*
0-62mph (sec):		7.5		7.3		5.4		4.6
Fuel consumption (mpg):		34.0		27.9		24.1		19.7
CO2 emissions (g/km):		N/A		N/A		N/A		N/A
On sale: March 2006		Prices (OTR): £58,975–£98,270		* Electronically limited