When the S320 was launched in India three years ago we had fallen for its radical air suspension, creamy V6 and luxury liner comfort. The revised S350 with its larger capacity engine and subtle revisions is better. But can it still hang on to the title of the best car in the world?

"The S-class embodies everything you could possibly desire."

Imagine the QE2, vast and luxurious, gliding over the seas, scattering lesser craft as it passes. Then, imagine the Mercedes-Benz S350L, and the impression is much the same, of a splendid behemoth, far ahead of anything else in its class, a single journey in which makes you feel immeasurably rich. M-B's limousine is, by popular vote, the best car in the world, and now it has been refined further. The S350L replaces the S320L, adding a bigger engine, a revised interior and a few cosmetic tweaks, and attempts to stamp its authority even more firmly as the luxury saloon to have. Anywhere.

Revised S-class takes the super-luxury car game to a different plane.

The styling, always elegant, always successful at hiding the bulk of this car, has received subtle tweaks. So how do you tell this face-lifted S-class from old? At the front the grille is more prominent, the lower intake widened and the front lamps given clear lenses. There are new wing mirror casings and the rear lamps have been gently reworked - they now appear striped. The new nose treatment adds fractionally to the car's five- metre length but otherwise British designer Steve Mattin's taut, elegant proportions are unchanged and work as well as they did four years ago, when this generation of S-class (W220) was launched.

Mercedes says that there have been 2100 component revisions and many of them are under the long bonnet and inside the cabin. The car is badged a 350 but engine capacity is actually 3.7 litres. In an effort to reduce costs, Mercedes engines now share heads, pistons, cranks and even camshafts. For example, the construction of the SL500's five-litre V8 engine and the S350's V6 are actually almost identical, the V8 merely having a couple of additional cylinders. The jump in capacity, along with small changes to the inlets and combustion chambers, mean that power has increased by 6bhp to 230bhp, due to Indian fuel.

The S320 we tested a couple of years ago was no slouch and the 350 is even quicker but marginally so. Zero to 100kph is despatched in an impressive (remember the 1.8-ton kerb weight) 9.56 seconds with 150 attained in 19.64 seconds. Also, notice that the 350 will motor you from 100 to 150kph in a scant 10.08 seconds. Floor the long travel accelerator and the big S-class feels like a 747-400 with all four Pratt & Whitneys on full shove - smooth, strong, sustained acceleration that doesn't peter out even after you've crossed the 200kph mark.

Performance within the city remains effortless and creamy and you hardly need to kick down on the superlative five-speed automatic to surge past slower cars, the healthier midrange showing up here. As with the 320, what impresses most is the consummate ease in which the performance is delivered, like being pushed forward by a giant invisible hand. The engine is virtually inaudible at most speeds and it's only when it nears the redline that you hear a distant hum from under the bonnet.

The interiors have been marginally freshened up as well. Sumptuous, spacious and adaptable to just about any body shape, there were few complaints, one of them being the endless array of switches in the S320, all rather small and plasticky, quite distracting while on the move.

This has been tidied up, especially in the revised instrument panel, and the centre console, where the plethora of switches has been replaced by an impressive-looking LCD screen, surrounded by buttons arranged in a more logical order. This is the COMAND system which controls a great many functions, reducing the number of switches and making access to them easier. A satellite navigation system is standard but it has no function in India apart from looking pretty and displaying sound system info. Apart from this disappointment (no fault of Mercedes), the cabin is fantastic, and further infusions of wood, chrome and leather add to the super-luxury feel. The interior may not be spectacular, as in the BMW 7-series but the architecture is extremely graceful to look at and intuitive to use.

3724cc V6 pumps out a velvety 230bhp.

If God is in the details, this car has an entire galaxy of features beyond anything you have seen before, all intended to make your journeys even more comfortable and safer. There are brilliant seats and great climate control, and a treasure chest of gizmos, all immensely useful, and more important, fun to fiddle with. It is an absolute joy to feel the seat sliding quietly under you when you use the seat controls, intelligently arranged in a pictogram - further evidence of just how well thought out this car is.

If you're warm, you can switch on tiny fans in the car seat that cool your shirt; if you're cold, you can heat the modified seats or set the climate control to half a degree. And it is not only you who can do that: the climate control is divided into four zones, in front and back, and each zone can have its own climate settings, quite independent of the others.

The rear seats need special mention here simply because we haven't experienced anything like them. Contoured and bolstered with orthopaedic perfection, the rear seats recline as well with pneumatically adjustable lumbar supports to make them easily the most comfortable place on four wheels.

The only mysterious bit is the feeling of width - the cabin feels strangely narrow. In a car this big, you'd expect to feel like you're sitting in the middle of a football field, but it barely feels wider than an E-class. Besides, it's no fun for a third passenger seated in the middle who sits perched on a raised cushion with legs on either side of the tall transmission tunnel. Another gripe is the glovebox barely large enough to hold the thick owner's manual.

The sound system adapts automatically to external noise levels, the gearbox adapts to your driving style, the doors click shut on their own. The new PRE-SAFE system uses sensors to detect occupant position and send this information to the airbags and seat belts, helping to protect you further in a crash, along with the 10 (10!) airbags inside the car. All that is missing is a jacuzzi and a delectable masseuse. Mercedes does actually have seats that give you a massage, but they are not an option here. There's very little you need to do to make yourself feel special in this car. Especially when you're on the move.

Mercedes' flying carpet also boasts special skills on the wrong side of 120kph. Set the pneumatically adjustable dampers to their softest settings, settle the phone handset into the armrest between the front seats, turn the blower down to a whisper and Mercedes' creamy V6 will silently tug you forward on an endless wave of torque. Stretched out in the infinitely adjustable seats, all you hear are the creaks in the leather as your passengers change position. It feels like God has hit the mute button.

Literally afloat on a cushion of air and large tyres, the S-class glides like no other. Set on the softest settings, the S will literally float over minor undulations as if they don't exist. Larger ridges, potholes and speedbreakers are heard and felt to a certain extent, but the intensity is greatly reduced. Up the speed and a majority of even these intrusions disappear almost magically. Now the S-class swallows even the worst roads without a murmur from the suspension and only the minutest of deflections - 160kph feels like a hundred.

Adaptive dampers also mean the S-class will willingly play the greyhound, though its proportions are more St Bernard. Set on the hardest settings (there are three), the S all but shrinks. The suspension feels tight, there is very little roll or pitch and the very direct and superbly weighted steering allows you to point the S accurately in the direction intended. You soon forget about the proportions of the S-class and begin to enjoy yourself . While the S-class lacks the overall grip, agility and chuckability of the new E-class, you can derive a surprising amount of pleasure from driving this limo reasonably hard. Step out of the car after a drive on a winding road and we'll bet you won't remember the 17-foot (5.1 metres) length or the aircraft-carrier width.

This is also a car that, above all, demands absolutely no effort from either passenger or driver. You never feel the strain of driving such a large, heavy car. Even after a long ride in the city in a searing summer, or after a 500km cross-country jaunt, you emerge from this car as cool and fresh as a breath of mint. This is a rolling boardroom, as good as any office, except few offices are as well equipped. You can waft about all day in the S350L, and use it as a mobile base from which to control your vast industrial empire, which, unfortunately, you'll need to possess if you're going to own this car.

There are no carefully balanced compromises in the S-class - everything that you could desire has been fitted in, not a single corner has been cut in the quest for the ultimate limousine. And that's why the S350L is still the best luxury car in the world.