Our view:
There can be few cars on sale today, or indeed that have ever seen the sodium-tinged light of a showroom, that totally define and dominate their sector like the Mercedes-Benz S-Class. Throughout its multiple generations, stretching right back to the Ponton saloon of the 1954, it has innovated and pioneered, debuting technologies never before seen on other machines. And, ultimately, that has kept it several steps ahead of any of its rivals.
However, in recent years, the gap to some of those competitors has got narrower, as they in turn have brought in ever more fancy technology and luxury overtones to challenge the S-Class' hegemony of the upper executive world. Indeed, Mercedes' two most local rivals, Audi and BMW, have really upped their games with the latest iterations of the
A8 and
7 Series respectively - the BMW to the point that, nowadays, if you get the spec of the Seven just right then (whisper this, but) it might even be better than the S-Class... - while even
Lexus' sumptuous LS 600h is knocking rather insistently at the S-Class' stately front door.
Time, then, for updates to the king of four-door saloons. Facelifted for the 2018MY, the looks of the S-Class aren't much different, because they didn't need to be - in long-wheelbase format like our test car, it still has a graceful yet intimidating presence that smacks of so much more than it being
'merely an enlarged E-Class'. Ditto the interior, which has those wonderful 'Widescreen' TFT screens for the main display and a level of fit and finish that simply oozes pure quality. Masses of space, too, in LWB guise.
No, what's happened is the Merc has gained some new drivetrain hardware, in this instance the new inline-six 2.9-litre turbodiesel, which is coupled to a nine-speed 9G-Tronic automatic transmission. And, with the stretched wheelbase of the 'L' model and Mercedes' absolutely peerless Air Body Control suspension set-up, what you have here is a car which is basically 5.25 metres of sheer, unadulterated luxury.
The 2.9-litre unit is a gem. It revs smoothly, it introduces no vibrations whatsoever into the S 350 d's plush cabin and, while it is admirably acoustically damped from idle to redline, its nicely refined growl permeates into the passenger compartment at just the right level to convey to its driver a feeling of muscular superiority over other road users. The straight-six diesel finds the perfect accomplice in the 9G-Tronic, which never once makes you mutter 'and why, precisely, do I need nine gears, pray tell?'. Instead, the gearbox is unctuous, cog-swapping fluidity, allowing you to mine the colossal 600Nm seam of torque the S 350 d has running through 2,000 revs of its lower-midrange time and time again.
But it's the ABC's ride quality which is the star attraction. Try as we might, we just couldn't find any road surface which left the S-Class flustered in the slightest. It glided peacefully and gently along, everywhere it went: through towns infested with drain-replacement, roadwork-ravaged surfaces; along country lanes rucked up by both years of underinvestment in repairs and enough tree roots to fill half of Sherwood Forest; up and down motorways and big dual-carriageways, that switch from corrugated concrete surface finish to smoothed-off tarmac surface finish like there's some kind of comedy patchwork-quilt road-laying gang in operation with the Highways Agency... and the Mercedes stayed utterly composed as it smothered out the whole blinkin' lot. Across 12 hours and more than 350 miles behind its wheel, it was a total delight to cruise in for every single millimetre and second of our custodianship of it. It even gave back 38.6mpg overall, returning a best of 45.5mpg on a trip to Harrogate and back. From a huge, heavy car with a decent turn of pace like this, that's nothing short of remarkable real-world fuel economy.
Of course, one of the things the S-Class has never truly excelled at is fizzing driving dynamics and the same is true of the facelifted W222. The steering remains overly light and while the Mercedes has a clean, calm manner to its cornering, it never feels like it wants to do anything other than approach and then pass through a bend at a level of less than seven-tenths commitment. But that's no drama; it's such a mesmerisingly comfortable car to travel in that you kind of forgive its lack of ultimate chassis edge. Also, it's one of the last Benzes in this part of the world with a proper 'gunsight' badge standing proud of its radiator grille, which is a magnificent design feature that ought to be brought back throughout the German brand's entire range, we feel - if it can meet pedestrian safety regulations for the S 350 d, why not for the A-Class or the GLC and so on? Nothing shouts imperiousness like a three-pointed gunsight.
In truth, S-Class stands for
Sonderklasse, the German term for 'special class'. And there are few cars in the world, of any shape or size, that feel any more special than this S 350 d L. Just as the luxobarge co-conspirators planned to depose the king from his throne, he foils their plan once more with an assured display of supreme control and diplomacy. Thus, the superb Mercedes S-Class has edged itself back in front of the pack once more, moving back to the rightful position it has long always occupied.
