2021 Mercedes-Benz S580e PHEV review: International first drive
Meet the most advanced production car to ever wear the three-pointed star.
- Top-shelf performance and an extended pure-electric range all in one
- Optional rear-axle steering system makes for outstanding agility and manoeuvrability
- Superb ride quality
- Newly designed interior is big on clarity and ergonomics
- Overall quality, richness of materials
- In-house nine-speed automatic gearbox not as smooth shifting as some rival units
- Latest energy-harvesting technology gives brake pedal a rather dead feel
- Weight gain over predecessor
- Early models 4G compatible only – no 5G upgrade available
Not since the very first Mercedes-Benz-branded models started rolling from the production line in 1926, has Mercedes-Benz attempted to produce something approaching the engineering complexity and sheer technical ambition of the new S-Class. A car that is destined to be produced exclusively in four-door saloon guise, following a decision to not replace the existing coupe and cabriolet models.
“In investment terms, no other Mercedes-Benz model comes close,” says Jürgen Weissinger, the man charged with the development of the seventh-generation S-Class and its new sister model, the upcoming electric-powered EQS.
The new S-Class is not just new. It represents an entirely different engineering and technical philosophy to the model it replaces. One that is based around electrification, digitalisation and connectivity, albeit within the flagship Mercedes-Benz saloon’s traditional values of performance, comfort and refinement.
It is the first Mercedes-Benz model developed to drive fully autonomously without a driver, if only within the confines of a suitably networked parking garage. It will search for empty bays and park itself fully remotely as part of a newly developed Park Pilot system, which draws on Level 4 autonomous driving technology not yet offered by any competitor.
Further, the new S-Class supports Level 3 driving at an EU-prescribed top speed of 60km/h on, at first, selected sections of German autobahn as a function of a new Drive Pilot system. This uses Lidar, among a veritable armada of short- and long-range radar, ultrasonic sensors, cameras and, so it’s claimed, the most advanced GPS to ever feature in a production car.
Another first is over-the-air capability, which allows remote software updates to over 50 different components throughout the new Mercedes-Benz model via an embedded SIM card.
It is a bold leap in technical terms even by S-Class standards, driven by recent advances made by upper-luxury rivals such as the latest Audi A8, Lexus LS, facelifted BMW 7 Series and Tesla Model S no less, and Mercedes-Benz knows it. You could sense the nervousness of its normally self-assured engineers during the new model’s launch in Germany last week.
Yes, the new S-Class heralds in many new developments, but it is relying on some tried and trusted drivetrains as it enters production in the form of two inline six-cylinder engines, both carried over from its predecessor with mild upgrades.
Included is a turbocharged 2.9-litre diesel developing 210kW in the S350d (available in some markets in both standard rear-wheel- and optional 4Matic four-wheel-drive guises) and 243kW in the S400d 4Matic.
It is joined by a turbocharged 3.0-litre inline six-cylinder mild-hybrid petrol unit with 270kW plus 16kW in the S450, the only model currently confirmed for sale in Australia, and 320kW and 16kW in the S500 4Matic.
Further engines are planned to follow by the time Australian deliveries get under way during the second quarter of 2021, including an AMG-developed twin-turbocharged 4.0-litre V8 mild-hybrid petrol engine that kicks out a none-too-subtle 370kW together with an additional 16kW from an integrated starter motor in the new S580.
It is Mercedes-Benz’s latest plug-in hybrid system that we concentrate on here, though. It uses a combination of the S450’s turbocharged 3.0-litre inline six-cylinder engine with a gearbox-mounted electric motor to provide the new 2021 Mercedes-Benz S580e with a combined system output of over 375kW and an electric range of up to 103km, or more than double the zero-emissions capability of its predecessor, the S560e, on the WLTP test cycle.
That’s not all, though. The upcoming S680 Maybach will maintain an S-Class tradition started in 1992 by continuing with an updated version of Mercedes-Benz’s twin-turbocharged 6.0-litre V12 petrol engine, which is claimed to better the 463kW of the S650 Maybach it replaces.
No lack of engines, then. But what of the looks – always a key S-Class identifier? The evolutionary styling changes brought to the exterior should go down well within the conservative realm of the upper-luxury car buyer.
It is a predictable update, with a much bolder grille, more angular headlamps that come with Mercedes-Benz’s outstanding Digital Light technology as an option, and traditionally smooth and unadorned flanks. Also, new horizontally mounted LED tail-lights extend into the rear of a sloping boot lid to set up a rear-end appearance similar to the third-generation CLS. In the UK, all models will feature the AMG styling package as standard.
For the first time on any Mercedes-Benz models, customers get to choose between two different types of door handles: conventional grip handles similar to those used by the existing generation of Mercedes-Benz models come as standard, while new flush-fitting electrically operated handles, which pop out as you approach with the remote key fob, are offered as an option.
The latter are part of a wide range of aerodynamic developments, including an almost flat underbody, that combine to provide the new S-Class with a class-leading drag coefficient of 0.22 – down from the 0.24 of the car it replaces.
The improvement in aerodynamics comes despite a moderate increase in dimensions. Overall, the new luxury saloon is 34mm longer, 55mm wider and 12mm taller than before. The latest, heavily re-engineered version of the German carmaker’s MRA (Modular Rear Architecture) platform also receives a wheelbase extended by 51mm over that of its predecessor at 3216mm in long-wheelbase guise.
A key development is the S-Class’s new rear-wheel steering, which can be specified with two different levels of steering assistance to the rear wheels: one with a rear steering angle of up to 4.5 degrees, as fitted to our test car, and another, more advanced arrangement with a rear steering angle of up to 10.0 degrees. As a result, the turning circle of the long-wheelbase S-Class 4Matic is reduced by a respective 0.9m and 1.9m at 11.9m and an impressive 10.9m respectively.
The standard suspension mates Mercedes-Benz’s AirMatic air-sprung system with the latest generation of its ADS+ adaptive damping control. It is offered alongside an advanced new E-Active Body Control set-up from the latest GLE and GLS.
Inevitably, the larger dimensions lead to an increase in kerb weight. Despite the greater use of aluminium within the body (it now makes up around 60 per cent of the complete structure at the expense of steel), the S580e tips the scales at close to 2200kg, due in part to its much larger battery, which is claimed to weigh 241kg on its own.
Open the door and the apparent conservatism evident with the exterior is instantly wiped aside by a brilliant interior. It represents an entirely different approach, not only in terms of design but also ergonomics, comfort and accommodation.
The dashboard, trimmed with a large panel of wood that extends into the front door trims and topped by a quartet of small rectangular vents, has distinctive maritime overtones. It is the two separate digital displays upon which you inevitably focus your attention from the broad and softly cushioned driver’s seat, though.
Included is a 12.3-inch screen (with an amazingly effective optional 3D function that provides an unparalleled depth of field) for the instruments, together with a separate 11.9-inch portrait-format central touchscreen that incorporates controls for the air-conditioning and other functions.
Ahead of the driver is a newly developed double-spoke steering wheel, which features a twin-zone sensor within the leather-lined rim to detect when the driver is properly gripping the wheel. In addition, there are new touch control buttons that function capacitively and shift paddles for the gearbox.
It is an appealingly uncluttered driving environment with a fitting richness to the materials – and it all proves relatively straightforward to operate right from the moment you hit the start button.
Overall, there are 27 fewer analogue controls than before, with the emphasis shifted to swipe, conversational voice and gesture controls via Mercedes-Benz’s MBUX operating system that boasts a claimed 50 per cent more computing power than the old COMAND system used by the last S-Class.
Accessing the various functions via the main menu within the central touchscreen is easy, though it takes more time to familiarise yourself with the deeply stacked sub-menus. There is no rotary controller any more, and the fiddly touchpad incorporated in more recent Mercedes-Benz models has thankfully been consigned to history, too.
Supplementing the two high-definition displays is a terrific new head-up display unit featuring augmented-reality functions for the first time, within a much larger display area than before. Another noteworthy option is a new flagship Burmester 4D sound system with 31 speakers, as well as subwoofers integrated within the backrests of each of the front seats, meaning you not only hear the music it plays but physically feel it, too.
The rear, meanwhile, can be optioned with two high-definition 11.6-inch touchscreen displays mounted on the back of the front seats, also using the MBUX operating system. This is in combination with a portable tablet through which occupants can access various functions, both inside and within close proximity outside the car, when the ignition is triggered.
While accommodation up front is virtually unchanged, the rear benefits from an added 16mm of head room, 24mm of leg room and 11mm of elbow room compared to the old S-Class in long-wheelbase guise.
Boot capacity has also increased by 20L to 550L on the non-plug-in hybrid models, though the mounting of the battery up back robs it of 180L of space, reducing it to 330L in the S580e – albeit with a totally flat floor, which is something Mercedes-Benz was unable to engineer into its predecessor, the S560e.
Overall, there are 10 airbags as standard. A further eight airbags are available as an option for the rear, including a newly developed airbag that deploys from the back of the front seats. In addition, Mercedes-Benz has provided the new S-Class with over 20 standard driver-assistance systems, including the new autonomous set-ups mentioned earlier.
Our first drive of the new production S-Class comes on a combination of fabulously smooth autobahn and country roads. And in its top-of-the-line S580e guise it immediately feels quick, incredibly refined, and very agile for such a large and heavy car.
The S580e’s ability to set off in complete silence and travel for truly extended distances of up to 103km on its electric motor alone is impressive enough in itself. This provides it with the sort of zero-emissions capability to cover most urban commutes without the need for its six-cylinder combustion engine to ever fire in anger.
With 110kW from the electric motor alone, it isn’t exactly rapid in electric mode. However, the presence of 440Nm of torque the moment you nudge the throttle provides for spritely step-off and relaxed cruising qualities at speeds up to 140km/h.
The secret to its impressive electric range is a large 28.6kWh lithium battery made up of 108 pouch cells mounted underneath the boot floor.
By comparison, the S560e, which used an older turbocharged 3.0-litre V6 petrol engine in combination with a gearbox-mounted electric motor, used a 13.6kWh lithium-ion battery and boasted an official range of just 50km on the older NEDC cycle.
What makes it truly special, though, is the performance the two power sources develop when they are combined. With a combined system output of 375kW and 750Nm – some 25kW and 50Nm more than the old S560e – there is crisp response, huge flexibility and enormous potency in Hybrid mode. All this and claimed combined-cycle consumption of between 1.3 and 0.8L/100km, and average CO2 emissions of between 30 and 18g/km on the WLTP cycle.
The potency extends to its charging. The top-of-the-line S-Class comes with a 3.7kW AC charger as standard, but supports charging on both an optional 11kW AC system and 60kW DC system. The latter of which is claimed to provide it with a full battery charge inside 30 minutes. The fuel tank capacity, meanwhile, is put at 67L.
As with the earlier S560e, drive is channelled through an in-house-produced nine-speed automatic gearbox and Mercedes-Benz’s 4Matic four-wheel-drive system, which uses a central differential to apportion drive between the front and rear wheels.
All up, there are four different driving modes: Battery (which ensures the combustion engine is always running to keep the battery topped up), Electric, Comfort and Sport. An additional Individual mode allows you to tailor the characteristics of the steering, throttle and damping to your liking.
It is in Comfort mode where the new S-Class is arguably at its compelling best. Here, the electromechanical steering in combination with the milder of the optional rear-axle steering systems is light but encouragingly accurate, and the engine is suitably subdued both in typical stop/start traffic and at constant cruising speeds.
Furthermore, the ride, at least on the optional E-Active Body Control air-sprung suspension used by our test car, is superbly supple in its actions – almost as if it is gliding totally isolated from its surroundings.
On smooth-surfaced German roads, it filters out small bumps with outstanding shock absorption and great isolation from the road surface. The overall refinement is truly exceptional, making it a very cosseting car to travel in over extended distances.
There is a distant hint of exhaust roar as engine revs rise before the gearbox quickly chooses a higher ratio. But like the lick of wind around the exterior mirror housings and tyre noise, it always remains distanced from the serene surroundings of the leather-lined cabin.
Switching into Sport mode is a quick and simple process, either via one of the few remaining analogue switches or via the digital Drive Select menu within the central touchscreen display. So configured, the new S-Class takes on a distinctly keener, more responsive and terrifically agile feel for such a big car.
The first hint of this is through the steering, which weights up accordingly. The throttle gains added sensitivity, while the exhaust note also becomes more present, though not exactly melodious. Additionally, there’s a firming up of the suspension to rein in body movement.
Outside the confines of city driving, the added weighting within the steering adds confidence, the S580e 4Matic turning fluently into corners with a level of agility beyond that of the old S560e. This is thanks in part to a Curve mode function within the suspension that tilts the new S580e into corners to reduce lateral forces.
There is added sharpness to its turn-in properties, and the steering is quicker to return to the straight-ahead than before, too. It is wonderfully easy to drive within its limits over winding roads, the only real limiting factor being its added width on narrow roads – well, that and its excessive weight.
There is a sense the new Mercedes-Benz model flows more keenly from apex to apex, its substantial weight hidden beneath a new layer of dynamic excellence. The quick reactions of the three-chamber air springs of the AirMatic suspension quickly quell pitch and dive while providing outstanding body control.
It takes more time to settle than lighter versions of the new S-Class when exiting corners; however, it is nevertheless very impressive in the way it shrugs off lateral forces. The fast-acting properties of the 4Matic four-wheel-drive system also ensure there is always plentiful grip and excellent levels of traction.
It’s quick, too, sprinting effortlessly to three-figure speeds and beyond on German autobahns. Extend the throttle towards the end of its travel and the mountain of torque helps to dispatch the S580e 4Matic down the road with a level of energy defying its combustion engine’s relatively modest capacity.
Mercedes is yet to announce a 0–100km/h time, though expect it to be under 5.0sec. Top speed, meanwhile, is limited to 250km/h.
It is not perfect, though. The gearbox, while inherently smooth at lower revs in automatic mode, is sometimes caught out when you shift manually near the combustion engine’s 6200rpm redline, with a less than subtle shift action as the S580e’s heady torque loads are deployed via the 4Matic four-wheel-drive system to each axle.
Mercedes has also provided its newest plug-in hybrid model with a new three-stage regeneration system, with the result that the brake pedal feels oddly over-servoed and has a rather spongy feel to its initial travel.
They’re minor criticisms in a car Mercedes-Benz still calls a pre-production prototype, so you'd expect they’d be rectified by the time it sees production next year.
Invariably, you step out of the new S-Class more relaxed than when you enter it. It is a car that enhances your wellbeing as effectively as, if not better than, any key luxury-class rival over any given journey. But there’s more to it than pure comfort and serenity of progress – the new Mercedes-Benz saloon also delivers on the driving front, too.
The model driven here boasts greater performance potential and handles with far greater precision than the S560e. More’s the pity for those who will only ever experience it from the rear seat.
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