Mercedes-Benz CLS350 vs Mercedes-Benz S450

What's the difference?

The Mercedes-Benz CLS has proven to be a niche hero, creating a segment and then evolving into something even more elegant, while keeping its unique appeal. A beautiful, modern cabin and the new engine in the CLS 450 provides the swiftness to match those looks.

Mercedes-Benz set out to restore the S-Class' place amongst the greatest sedans in the world.

In the heavily-optioned, near-$250K-plus S450 as well as the extended S450L at $300K as tested (the sweet spot of the range for now), we reckon the Germans have succeeded, pushing safety, comfort and technology boundaries, in a package that is true to the heritage of the series.

Tax-fuelled sky-high prices will certainly keep the S-Class niche in Australia, but the car is more than good enough to dominate its tiny corner of the upper-large luxury car sphere.

The best new car in the world? We reckon it's highly likely. Mission accomplished, Mercedes.

The new-generation CLS has arrived looking slipperier than a cake of soap on the bottom of the bath. This model has always had svelte styling, but things have become even smoother with Benz’s design chief Gorden Wagener insisting more lines be removed in the creation of this latest version.

So, while there’s the familiar profile of that roof tapering down into the boot lid, the long rear overhang and that sliver of a window opening arching and turning down sharply at the rear, it's a more flowing design now that there are less edges to break it all up.

A new ‘shark nose’ grille opening, and broad bonnet adds a hunk of muscle car toughness to the CLS’s face. But it’s refined thuggery, with that single-louvered ‘diamond studded’ grille flanked by flush-mounted headlights. The tail-lights, too, are so contoured to the body around them they look painted on.

As CarsGuide senior editor Matt Campbell pointed out in his review of the CLS at the international launch, the car looks far better in the metal than it does in any photo.

The CLS is based on the E-Class, sharing its platform and technology, but it’s about 20mm longer (at 4988mm) end-to-end. That’s almost 50mm longer than the previous generation CLS, too. At just over 1.4m tall the CLS is low-slung but wide at 1.9m across (almost 2.1m including mirrors).

The CLS’s cabin mirrors that of the E-Class, too, with a sweeping dashboard which flows through into the doors, two large landscape displays for your instruments and media, an oversupply of air vents and some darn sexy lighting. It’s a luxurious, stylish, comfortable, but snug setting cocooned by padded leather and polished surfaces.

The Australian CLS has been fitted standard with the AMG interior and exterior packages.

You can pick from 11 colours – eight of which are no-cost options and include, 'Polar White', 'Obsidian Black', 'Iridium Silver', 'Citrine Brown', 'Graphite Grey' and 'Cavansite Blue'. Optional colours include 'Hyacinth Red' and 'Selenite Grey Magno'.

Most Mercedes models have followed the Russian Doll-style cookie-cutter styling theme, and the heavy family look continues with the W223.

Still, the flush door handles do add a touch of Tesla-esque modernity, while the elegant silhouette and clean lines are in keeping with the luxury aspirations. Larger in every dimension compared to the old W222, the S450 is some 71mm-longer in wheelbase (3106mm) than before while the LWB's has stretched out by 51mm (3216mm), benefiting proportions as well as interior packaging.

AMG-branded wheels look sporty but – in the S450 at least – they're perhaps a tad too gangster. A set of flush alloys would give it a more-modern and techier appearance, in our opinion.

Overall, however, the S-Class ‘7' possesses the prerequisite richness of design. It isn't as bold and mould-breaking as models like the W116 were back in their day, but the styling is still a success.

By the way, the latest S-Class is the first Mercedes to employ the MRA2 longitudinal platform, which is rich in lightweight steels (50 per cent aluminium), is correspondingly stronger than before but also 60kg lighter.

With a drag co-efficiency rating as low as 0.22Cd on some overseas grades, the W223 is one of the most aerodynamic production vehicles in history.

Remember how I said you were going to have to surrender something if you wanted a CLS? Well, yes, you’ve have to surrender your hard-earned money, but you’ll also have to give up quite a bit of practicality.

That swooping roofline makes entry into the front seats a bit precarious for people of my height (191cm) trying to swing themselves into the cockpit without clocking their heads on the A-pillar.

The impracticality only gets worse with entry into the back seats, and legroom in there for me is tight, too.

I can only just sit behind my driving position thanks to the contoured seat backs. Headroom is also limited.

It’s worth pointing out that this time the CLS is a five-seater – the previous generation sat just four.

Storage isn’t bad, running to a deep centre console bin with a split lid, there are two cupholders up front and another two in the rear fold-down armrest along with another covered drawer, and all doors have small bottle holders.

The CLS’s boot capacity is 520 litres, and the rear seats fold 40/20/40 to provide extra space.

For the beginning of our day with the S-Class, we were chauffeured from home to a mansion in Kew, a blue-chip Melbourne suburb. Our heavily-optioned S450L featured most of the aforementioned extras – including the Business Class Package and Rear Entertainment Package – and the experience was predictably, sumptuously memorable.

Reclining individual rear seats with easy-reach tablets, armrests offering access to all multimedia and available climatised and massaging cushions and backrests... we're no longer in our normal ride, Toto.

Yet, all these trinkets and gizmos are mere add-ons, that can turn a stretched Caprice into a flash hen's night carriage if enough money and glitz is thrown at it.

No, the new S-Class must impress in an altogether less tangible and more philosophical manner, involving all the senses, and not just what we see, hear and touch. It must appeal beyond the superficial. Otherwise, it is not a large Mercedes-Benz luxury sedan in the classic manner.

This is a Herculean task for the Stuttgart designers and engineers. By and large, though, the Three-Pointed Star has succeeded in achieving something special.

In its perception of peerless quality and engineering, the W223 is striving to move forward and look back simultaneously to the glory days of the seminal W126 (1980-1991). This is through meshing traditional virtues like solidity and quality materials while dazzling its passengers with technology that is still friendly enough to want to enhance your experience.

You can sink into the soft lounge seats, watch the world pass by silently outside and never be aware of the road underneath or the engine ahead. Double glazing, exquisite and aromatic fabrics and materials and lush tactile surfaces work their magic inside the car, while an airtight and aero body, solid platform, air suspension and a muted yet muscular powertrain all do their thing underneath. The atmosphere is special and rarefied. That's what an S-Class needs to be and that's what is happening in our $299,000 (as tested) S450L.

The same more-or-less applies up front, as the same trim, leather, wood and technology surrounds the driver and passenger. The spectre of the car that is surely The Car of the Last Decade – Tesla's Model S – is evident in the portrait touchscreen and sparse, almost wallflower dashboard design and layout. No big imposing architectures here.

Yet, while the American upstart actually takes stuff away, the S-Class packs the cabin with subtle features that – like when the planes stopped flying last year and the birdsong subsequently returned – only become obvious once the cabin's design simplicity clears all the white noise for you to be in a better frame of mind to enjoy them.   

Take the haptic interface, for example, as it is perhaps the best we've experienced; the sense of well-being garnered from the cumulative effects of profound seat comfort (the massaging function was never switched off), cocooning micro climate environmental control, orchestral levels of audio entertainment and the theatre of light and vision performed by the two available screens; it is an automotive experience like no other. And the eye-tracking 3D-effect navigation set within the electronic instrumentation. No need for cinematic glasses to get the effect. The driving position itself, by the way, is also first class.

Room to stretch and grow for sure, and in every direction. But room for improvement? You betcha.

Your tester had a headache after a little while staring at that woozy 3D map. The central vents – four at the front, two in the rear – look and feel cheap, leaving us mentally redesigning them; they are frightfully out of place here; the carryover column-stalk auto lever should have been binned in 2005. And, even though the digital instruments have a number of options, none are elegant enough for the S-Class. That's an especially subjective criticism, clearly, but one that – in the context of classic Mercedes luxury sedan contenders – is justified given how timeless the Bruno Sacco era of Daimler design was. Look him up, kids.

Still, after a couple of hours behind the wheel, with our senses reset to calm, it is obvious that the S-Class cabin is a unique and wonderful place – as it should be at a cool quarter-of-a-million dollars.

Job done.

PS At 550 litres (20L more than before), the boot is massive and luxurious enough to sleep in.

Right now, only two S-Class models are available – the S450 from $240,700 plus on-road costs and the 110mm extended-wheelbase S450L (LWB) for another $24,900 on top. Most buyers overwhelmingly opt for the latter.

Despite what the numbers may suggest, both are powered by a 3.0-litre in-line six-cylinder turbo petrol engine, delivering 270kW of power and 500Nm of torque to all four wheels via a nine-speed torque-converter automatic. Greater choices are coming later, including an all-electric version known as the EQS.

Almost every conceivable safety item is standard on the S-Class, including world-first rear-seat airbags located behind the front seats in the LWB model, taking the surround-airbag count to 10.

You'll also find route-based Speed Adaptation (adhering to the posted speed limits), Evasive Steering Assist (a sophisticated form of crash mitigation), adaptive cruise control with active stop/go, Active Lane Change Assist that automatically moves the car into the lane you indicate to), Mercedes' PreSafe crash-preparation tech that primes all the safety systems for impact, electronic stability program that encapsulates all the active driver-assist tech, Active Emergency Stop Assist, Autonomous Emergency Braking front and rear (including for cyclists and pedestrians), Traffic Sign Assist, Parking Package with Active Parking Assist and 360-degree camera and tyre pressure monitors.

On the equipment front there is the latest iteration of Mercedes' MBUX multimedia system with (another) world-first 3D display, complementing an OLED central display, powered closing doors, leather upholstery, air suspension, leather upholstery, velour floor mats, a multi-beam LED headlight system with adaptive high beams, heated and folding exterior mirrors, heat and noise-insulating acoustic glass for front side windows, dark privacy glass for rear windows, sunroof, roller sunblinds for rear windows, metallic paint and 20-inch AMG alloy wheels on runflat tyres.

Want cutting-edge multimedia? There's MBUX II's augmented reality for navigation and fingerprint scanner, as well as a more natural-speech Mercedes-Me Connect voice activation with global search.

Plus, predictive navigation with live traffic, parked vehicle locator, vehicle tracking, emergency call, maintenance management and tele-diagnostics, digital radio, Burmester 3D surround-sound system with 15 speakers and 710W amplifier, remote door locking/unlocking, geofencing, speed-fencing, valet parking, head-up display, Smart Phone integration with Apple CarPlay/Android Auto, wireless charging, ambient lighting, two-zone climate control, poplar wood trim, electric adjustment for front seats, steering column with memory function, climatised front seats, keyless entry/go with flush-fitting door handles offering hands-free access (including for the electric boot),

Besides the ‘forward facing' airbag for the rear-seat occupants, the S450L also scores electrically adjustable rear seats with memory and automatic rear climate control.

Key options – and the list is massive – include an $8700 Rear Entertainment Package, that brings rear-multimedia access, rear tablets with wireless headsets and rear-seat wireless smart phone charging, an AMG Line pack with a body kit, different alloys and larger front brakes ($6500), Business Class Package that includes aircraft-style reclining rear seating and tray tables ($14,500), Nappa leather ($5000), augmented-reality HUD ($2900), 21-inch wheels ($2000) and four-wheel steering ($2700). There's also a $14,500 Energising Package with contoured seating, heated-everything and massaging seats.

Please keep in mind our test cars featured many such extras. Tick all the boxes and you can add nearly $100,000 to the price of your S-Class.

So, is the S450 good value? Given some of the breakthrough safety and luxury features it offers, it is unique. Too bad the Federal Government's Luxury Car Tax makes them so much more expensive than they need to be.

If you’ve skipped straight to this bit you’ll have missed news that there’s no longer a diesel engine in the CLS line-up. Instead you have a choice of three petrol engines – one for each grade and all of them are new to the model.

The CLS 350 has a 2.0-litre four-cylinder turbo-petrol engine producing 220kW/400Nm. That grunt is delivered to the rear wheels via a nine-speed automatic.

The CLS 450 4Matic has a 270kW/500Nm 3.0-litre in-line six-cylinder engine with a twin-scroll turbo and like the Mercedes-AMG 53 above it has an integrated electric motor called an EQ Boost. While it’s a hybrid system of sorts the electric motor doesn’t drive the wheels, instead it recuperates kinetic energy and charges the battery.

The CLS 450 uses the nine-speed auto, as well, and is all-wheel drive.

The Mercedes-AMG CLS 53 4Matic has the same transmission and engine as the CLS450 but has been given a heftier twin-scroll turbo charging system and tuned to produce even more grunt at 320kW/520Nm. The 'EQ Boost' performs the same function as in the CLS 450, but also provides power to an electric turbocharger. The Mercedes-AMG CLS 53 4Matic is also all-wheel drive and uses a nine-speed automatic.

Where are the V8s?

Right now, the only W223 you can buy is powered by an all-new 2999cc 3.0-litre in-line direct-injection six-cylinder turbo petrol engine dubbed the M256, complete with double overhead cams, an electric compressor intercooler and assistance from a 48-volt mild hybrid system and integrated starter-generator, adding 16kW and 250Nm to the 270kW of power at 6100rpm and 500Nm of torque from 1600-4500rpm.

The 9G-Tronic torque-converter automatic transmission and 4Matic all-wheel drive system combination is a first for the S-Class in Australia.

Top speed is limited to 250km/h, while the 0-100km/h sprint-time takes just 5.1 seconds in both models. Impressive for a two-tonne-plus luxury limo.

This is a good place to remind you (again) that only one CLS grade was available to drive at the Australian launch – the CLS 450, and we were only given the claimed fuel economy figures for that model.

After 197km through, on a route that bumper to bumpered its way out of Melbourne CBD and headed the long way to the airport via Woodend. our car’s trip computer was reporting close to an average of 10.0L/100km.

With the aid of the mild-hybrid system, the S450 returned a combined average of an impressive 8.2 litres per 100km, which translates to 187 grams of carbon dioxide emissions per kilometre. 95 RON premium unleaded (or higher) is recommended. In the urban run it consumes 11.3L/100km (11.5 for S450L), and just 6.4L/100km (6.5 for S450L) in the extra-urban result.

At 76 litres, the fuel tank will allow a combined average range of about 927km between refills.

A reminder again, folks – Mercedes-Benz only had the CLS 450 available to drive. Okay? On with the review…

Nobody likes a traffic jam, apart from maybe taxi drivers. But sitting in a CLS deep in Melbourne’s CBD, stuck in road-work-infested roads, choked with cars going nowhere was as pleasant as the experience could be. 

Plush seats, pretty lighting, air filtered and fragranced, air suspension cushioning the patchy tarmac underneath as we wriggled our way north towards Mount Macedon and country roads.

If you read another review calling out a large degree of wind noise filtering into the cabin, they’re right and wrong. See, the weather was apocalyptic as we hit the motorway. Trees doubled over kind of windy, and sure you could hear it rushing past the windows when we were at 110km/h, but you could also hear it clearly when we were at 30km/h.

I like gadgets and so it was about 15 seconds into the motorway stint that I tested out the active cruise control, and automatic lane changing, which works near perfectly.

As the roads became more winding, I switched drive modes to 'Sport', firming up the suspension and steering, at the same time prompting the transmission to kick back into a lower gear.

This is a stable-feeling car, well balanced and effortless to steer. Smoothness is a word for everything it does, including covering the ground quickly.

While that acceleration is rapid, it’s not quite exhilarating, and the engine note under load is a little high pitched for a thug like this.

CLSs of the past were known for being a bit more aggressive and feistier, but this one seems to have mellowed in its third generation. I don’t see any issues with this. There are other angrier Benzs if that’s your thing.

In former times, as the Germans say, a ‘450' on the boot indicated V8 power. In the W116 S-Class era it was one of the world's most evocative badges when ‘SEL' was also attached.

As mentioned earlier, though, it's the M256 3.0-litre turbo-petrol with a 48-volt ‘mild hybrid' electrical system that's doing the driving, to all four wheels. The real V8 W223 will probably surface later this year or in early 2022 with the S580L flagship. Bring it on.

This is not to say that S450 isn't good enough. With that electrified assistance, the blown straight six is smooth and swift off the line and rapid as the auto seamlessly steps up through all nine gears. Because it's so hushed and refined, it doesn't feel 5.1s to 100 clicks quick, but watching the speedo says otherwise – acceleration is assertive and strong right up way past the legal speed limit.

All that's missing is the burbling soundtrack of a classic Benz bent-eight. Oh well. Outstanding economy is a price we're literally willing to pay in lieu.

Even more impressive is the S450's ability to hustle along mountain roads like an overgrown sports sedan.

Now, for Australia, all S-Classes are fitted standard with an adaptive ‘Airmatic' air-suspension set-up, including air springs and self-levelling tech. In Comfort up to 60km/h, the ride height can be raised by 30mm, or lowered by 10mm under the standard 130mm baseline in Sport at any velocity, while in Sport+ it falls another 17mm.

With that in mind, yes, the standard air suspension performs a magnificent job smothering out most surface imperfections around town. Yet its real other party trick is to tighten up the chassis when corners get interesting and Sport mode is selected. Aided by progressively weighted and reassuringly responsive steering, the Mercedes tips into turns with precision and poise, slicing through with virtually no discernible body lean or understeer.

Now, we're not talking a leisurely drive on rural highways here, but Healesville's famous Chum Creek Road, where even a Porsche Cayman would feel like it's had a strenuous dynamic workout. The S-Class can be hurried along with confidence and finesse, displaying outstanding handling and roadholding for a 5.2-metre long limo. And the fact that the ride quality only suffers marginally when the red horns are out is all the more remarkable.

Back in the cut-and-thrust of inner-city peak-hour traffic, the Benz in Comfort mode continued to reveal its driver-orientated yet passenger-focused twin-personalities, zipping in and out of gaps while remaining comfy and composed inside.

Only when parking in tight spots are you truly aware that the W223 is longer than a Mazda CX-9. The optional four-wheel-steering system is claimed to slash the turning circle to A-Class hatchback levels. 10.9 metres is the claim.

The 2021 S-Class never ceases to amaze and delight.

The W223 S-Class has not been crash-tested yet by ANCAP or European affiliate EuroNCAP, so does not have a star rating. However, Mercedes-Benz claims it has striven to create one of the safety vehicles on the planet. Who are we to argue?

Almost every conceivable safety item is standard on the S-Class, including world-first rear-seat airbags located behind the front seats in the LWB model, taking the surround-airbag count to 10.

You'll also find route-based Speed Adaptation (adhering to the posted speed limits), Evasive Steering Assist (a sophisticated form of crash mitigation), adaptive cruise control with active stop/go, Active Lane Change Assist that automatically moves the car into the lane you indicate to), Mercedes' PreSafe crash-preparation tech that primes all the safety systems for impact, electronic stability program that encapsulates all the active driver-assist tech, Active Emergency Stop Assist, Autonomous Emergency Braking front and rear (including for cyclists and pedestrians, at speeds from 7km/h to over 200km/h), Traffic Sign Assist, Parking Package with Active Parking Assist and 360-degree camera and tyre pressure monitors.

The Active Lane Keeping Assist works in a speed range of between 60km/h and 250km/h while Active Steer Assist helps the driver follow the lane at speeds of up to 210km/h.

The CLS is covered by Mercedes-Benz’s three-year/unlimited kilometre warranty. Servicing is recommended every 12months/25,000km for the CLS 350 and CLS 450, while the CLS 53, like all AMGs needs to visit at 12month/20,000km intervals.

Mercedes-Benz says a capped price servicing plan will be available, but has yet to release the prices. We’ll update this as soon as the costs have been announced.

Unlike many luxury brands that persist with a sub-par three-year warranty, Mercedes-Benz offers a five-year/unlimited kilometre warranty.

Intervals are every year or 25,000km, with a capped price service plan starting at $800 for the first year, $1200 for the second year and $1400 for the third year, totalling $3400. Alternatively, there is a Service Plan starting at $2700 for the first three years (saving $700 from the normal capped-price service plan), $3600 for four years and $5400 for five years.