| A Week at the Wheel | Cambs, England | Mercedes-Benz S 320 CDI |

Inside & Out:

Mercedes' designers pursued a completely different school of thought with the new S-Class and the looks are a departure from those that have gone before. Where the older generation S-Class designs looked every inch their size, Mercedes has consciously set out to answer critics by using subtle shape and form to disguise the newest S-Class's true dimensions. The long wheelbase car we tested is a full 5.3-metres long, but in isolation it doesn't look it; only when you try and slide it into a normal size parking bay does the enormity of the car become clear.

Inside, that long wheelbase pays huge dividends when it comes to occupant space - especially in the rear. Even with front seats at the full extent of their rearward travel, passengers in the rear enjoy an expanse of leg room found in very few other cars on sale. As you'd expect, comfort is top of the agenda and the focus is perhaps even more on those in the rear than the passengers up front. In either space, the occupants enjoy wonderfully comfortable seats and plenty of room. There is a full complement of toys, as you'd expect, and the 'Comand' centre does integrate these quite effectively. However, there are still an awful lot of buttons spread around the cabin that take a good amount of time and familiarity to interface with effectively.

Engine & Transmission:

A new three-litre six-cylinder diesel engine provided the propulsion in our test car and proved itself to be a smooth and willing unit. Outright power of 232bhp isn't that impressive compared with some rivals, but 398lb.ft of torque - available from 1,600rpm - is the much more important figure. Thanks to this low and mid-range urge, and combined with the smooth shifting seven-speed automatic 'box, it's possible to drive this car around at a reasonable pace without ever seeing more than 2,500rpm.

That's not to say that the S 320 CDI can't provide more sporting intent when called upon, the gearbox keen to shift down and exploit the power available, but in most cases, and in the hands of the majority of customers, the relaxed nature and delivery of the engine and gearbox combination suits a limousine perfectly. Needless to say it's also quiet and refined and an average economy of 30mpg effectively renders the S 280 petrol model redundant.

Ride & Handling:

Active air suspension allows the driver to tailor the chassis settings for the type of driving involved. Be it wafting around town, accruing motorway miles or a spirited B-road drive, the suspension does a very good job of containing the S-Class's size and bulk. The three settings can be selected at the press of a button on the fly (though unfortunately this isn't independent of gearbox function) and the cosseting nature it provides in the urban environment is perhaps only overshadowed by how agile and capable it proves to be when pushed hard.

Equipment, Economy & Value for Money:

As you'd expect in an S-Class, the list of equipment is expansive. To fully appreciate all of the options would take well over a week's worth of motoring and extracting the best from the systems and their interfaces takes time and patience. The list of technologies and associated acronyms is too long to explore in detail here but we'd pick the Comand system and Distronic adaptive cruise control as the two highlights that provided most benefit during our time with the car.

Of course, the raft of safety features normally associated with an S-Class are ever present, perhaps only making themselves felt on the one occasion they may be needed, when the worst happens, but their presence and functionality are reassuring. Value is a very subjective parameter to judge at this end of the market. In isolation £60,000 seems an awful lot of money for a car, but consider the space, technology, equipment, comfort, safety and style offered for that price and it's hard not to consider such an elevated cost as reasonable value for money.

Overall:

The Mercedes-Benz S-Class always impresses in almost any guise. This diesel version brings added benefits in terms of running costs with relaxed and muscular performance. Other rivals may offer a more exciting driving experience, but as a car to be driven in, the S-Class takes some beating. The Best Car in the World moniker may be reserved for the high-end petrol version, but this car runs it very close.