Category: Large Executive 
Price Range: £55,022 to £147,965
Remarkable refinement, especially lack of road noise. Agile for its size, rapid, fun to drive, laden with understandable and useful technology.
Looks brash and may date quickly.
With beauty on its side it would be a five-star car.
Where to begin? You don't need to read to the end of this test to realise how the new Mercedes-Benz S-class has moved the luxury-car goalposts. It does this not only with some ingenious and genuinely useful technology but also by being quieter and more cosseting than any of its rivals. Yet it's no floating, disconnected giant in which the driver plays but a bit-part: the grosser Mercedes is surprisingly agile and engaging to drive.
The previous S-class (W220 in Mercedes-speak) hardly seems old enough to be replaced, and has a kind of timeless beauty of a kind which Mercedes now seems to have abandoned. The new car (W221) is bigger, brasher, more imposing, and it features some revised engines plus a brand-new, 5.5-litre V8. One of the most visible bits of technology is the new Comand controller, clearly modelled on BMW's iDrive but much easier to use. You can even use it to adjust the shapes of the front seats via a 3-D pictogram on the display screen. Oh yes, and the sat-nav has a 20GB hard drive.
There's a new Brake Assist Plus function which uses two different frequencies of radar beams that also feed the improved Distronic Plus active cruise control. Not only does it warn you if you're travelling too close to the car in front, it also modulates the Brake Assist function so that instead of ramming the brakes on as hard as possible, it applies them only hard enough to prevent a collision thus reducing the likelihood of someone crashing into the back of you. The brake lights flash under heavy braking, too, and if the S-class's sensors detect an inevitable accident they activate an improved version of Pre-Safe, which now pumps up various parts of the seats to help cushion an impact as well as closing windows and setting the optimal seat positions.
Wrapping all the technology (there's more to come) is a body with an aerodynamic drag coefficient (Cd) of just 0.26, despite the upright front grille. The waistline has a convex curve beneath an equally curvaceous roofline, giving the S-class the look of a heftier, less graceful CLS. The bonnet, doors, boot and various underskin members are of aluminium, with much of the rest of the structure made from high-strength steels to make the result a little more rigid than before. The floor is stamped with irregular dimples, which not only makes the panels stronger but reduces their transmission of noise. Laminated side glass further helps in the quest for quietness.
Usual suspension fare is the Airmatic DC system with air-pressure springs and adaptive dampers, while Automatic Body Control (ABC) is standard on the S600 and optional on the others. Both systems have improved adaptability thanks to the inevitable higher computing power. Surprisingly, though, the brake-by-wire system pioneered on the SL and the E-class is absent, because it's harder to match it to the Brake Assist Plus function.
