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It may not be all-new, but the latest version of Mercedes' range-topping S-Class saloon sets new standards in refinement

What is it?

Listening to Mercedes-Benz outline the latest incarnation of the Mercedes-Benz S-Class at a press conference in Zurich, Switzerland last week, you could have been forgiven for thinking it really is an all-new model.

The latest S-Class features more than 6000 new components and three new engines – two of which are new to the model, including a six-cylinder petrol unit combined with an electric motor and 48-volt electrical system in a pair of mild hybrid models. There’s an updated infotainment system and a semi-autonomous driving system that can accelerate and brake by itself, including in and out of roundabouts.

But no matter how hard Mercedes-Benz tries to convey the step the latest S-Class has taken – and, admittedly, it is significant – it is still a mid-life facelift of the W222 model.

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That said, it is a facelift the Mercedes’ head of research and development, Ola Kallenius, describes as the most comprehensive in the company’s long history. Indeed, the latest S-Class appears to be right up there with the BMW 7 Series and the Audi A8 in technological terms, no mean feat for a car originally introduced in 2014.

Dimensionally, the S-Class hasn’t changed; it stretches to 5125mm in standard guise and a rather palatial 5255mm in long-wheelbase form.

The familiar exterior appearance remains, too. However, many of the details, including the prominently chromed grille, profiling of the bumpers as well as the LED headlamp and tail lamps graphics, have been updated to give the S-Class a fresher look.

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Underneath, it uses an updated version of the outgoing S-Class’s platform – a combination of the MRA platform used by the smaller Mercedes-Benz C-Class and E-class, with unique S-Class structural elements at the rear. It is allied to standard Air Body Control air suspension. Unlike the three-chamber system unveiled on the latest E-Class, though, the Mercedes-Benz S-Class retains the simpler single chamber air springs used on the outgoing model. 

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The electrical architecture has definitely been upgraded, and supports the widest range of driver assistance system of any Mercedes.

UK pricing is yet to be finalised, but is expected to be around £80,000.

What's it like?

We drove the S-Class 400d in long wheelbase form. It comes with rear-wheel drive as standard; our test car was fitted with optional 4Matic four-wheel drive.

The big change is the engine. Gone is the turbocharged 3.0-litre V6 diesel unit that has been a mainstay of the Mercedes-Benz S-Class line-up since 2005. It is replaced by an all-new turbocharged 2.9-litre in-line six-cylinder diesel motor that delivers 335bhp. It has 19bhp more power than the turbocharged 3.0-litre in-line six-cylinder unit used by the latest BMW 730Ld and 71hp more than the turbocharged 3.0-litre V6 engine in the fourth-generation Audi A8 3.0 TDI. The S-Class's engine features a stepped bowl combustion process, multi-channel exhaust gas recirculation system and, for the first time, variable valve lift control.

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The new in-line unit is smoother and more refined than the V6 it replaces. Barely audible at idle, revs build quickly, smoothly and linearly, with the S-Class’s new nine-speed torque converter 9G-Tronic gearbox, which operates in combination with a 2.47:1 final drive ratio, programmed to exploit the strong torque characteristics.

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While lacking the electric motor assistance of the 2.9-litre, in-line six-cylinder, petrol-powered S500, speed nevertheless builds quickly with merely a distant hum from the new engine detectable from the well-isolated cabin. With a strapping 516lb ft on offer at just 1200rpm, the new 2000kg S400d 4Matic’s in-gear performance is wonderfully punchy from anything above idle through to where it peaks at 3200rpm. Mercedes-Benz quotes a 0-62mph time of 5.2sec and a (limited) 155mph top speed, with official fuel consumption and CO2 emissions of 50.5mpg and 147g/km.

Behind the wheel, it's the superb ride that sets the new S-Class apart from the upper luxury car competition. On smooth surfaces it glides along in the finest traditions of its celebrated predecessors. The electronically controlled air sprung suspension maintains a pre-set ride height and sponges away blacktop scars with authority. Even over nasty transverse ruts, our 400d 4Matic managed to maintain ironfisted composure with the sort of inherent control and sensitivity unmatched by the latest 740d and the outgoing Audi A8 3.0 TDI.

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Switch the standard Dynamic Select system into Sport mode and it distinguishes itself with outstanding road holding and, with the optional Air Body Control suspension fitted to our long wheelbase model, exceptional body control given its generous dimensions.

The steering remains extremely light and a little vague in the first few degrees off centre, but it weights up nicely and is sufficiently precise with a quarter turn of lock to engage the driver. The four-wheel-drive S400d 4Matic serves up exceptional grip and the sort of cornering tenacity to allow swift and spirited progress over more challenging roads without constant interruptions from the traction and stability control systems.

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Inside, the front seats offer a tremendous comfort over longer journeys. The cabin styling has been subtly refined, with higher-grade materials within the dashboard, which remains dominated by two high definition displays for the instruments and infotainment system. 

In the rear, the long wheelbase provides exceptional leg room – something that arguably matters most at this end of the luxury car spectrum.

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There’s also an incredible amount of technology, ranging from a raft of driver-assistance systems to cutting edge semi-autonomous driving functions. While the S-Class can’t steer by itself for more than 30 seconds at a time, the autonomous accelerating and braking functions that come as part of an updated cruise control system are a clear step toward fully automated driving that Mercedes-Benz promises will be part and parcel of the next S-Class just three years from now.

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Should I buy one?

There will always be some who feel the need to arrive in something more exclusive than an Mercedes-Benz S-Class. Yet despite the cachet associated with a Rolls-Royce Ghost or Bentley Flying Spur it is arguable whether they manage to deliver the sort of wellbeing served up by the latest incarnation of the long-wheelbase Mercedes-Benz saloon flagship.

Those buying it to drive, or to be driven in, will experience an exceptional car perfectly judged to meet the demands of a discerning market.  

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Mercedes-Benz S-Class S400d 4Matic

Location Switzerland; On sale Now; Price TBC; Engine 6cyl, 2925cc, turbocharged, diesel; Power 335bhp at 3600rpm; Torque 516lb ft 1200rpm; Gearbox Nine-speed automatic; Kerbweight 2000kg; Top speed 155mph; 0-62mph 5.2sec; Economy (official) 50.5mpg; CO2 147g/km; Rivals Audi A8, BMW 7 series, Jaguar XJ

Join the debate

Add a comment…
sco1 21 July 2017

Why not test the new petrols? They are the true new technology

Wonder why you did not test the new 450/500 varriants. The true technology improvement (and a true diesel alternative) are the petrol s450/500 complete with 48v electrics, electric turbocharging, mild hybrid and low co2. Quoted figures for s500 are 4.8s 0-100 and Co2 of 150. Why settle for a diesel?

bomb 20 July 2017

400d not available in the UK

400d not available in the UK yet, this 18MY facelift range still comes with the 350d if you want a diesel.

Flametrench 20 July 2017

ABC or not?

Greg says Air Body Control is standard then (later) says it's optional?