Mercedes-Benz CLS-Class vs Audi S6

What's the difference?

Comfortable when it needs to be and sporty when you want it to be, the CLS 53 is a bit like Mercedes’ Doctor Jekyll and Mr Hyde – or maybe Bruce Banner and the Hulk is a better frame of reference for some.

While it doesn’t excel in any one particular area, its breadth of useability is commendable, but ultimately it might be its all-too-familiar aesthetics that is the biggest letdown.

From the inside, it looks and feels like any other large Mercedes model (not necessarily a criticism), while the exterior – in my opinion – doesn’t go far enough to differentiate it from the CLA.

After all, if you wanted a stylish and sporty sedan, shouldn’t feel special too?

We adore the new S6 sedan. It looks great, feels comfortable and goes like stink all at the same time. What’s not to like?

It also helps that it is relatively good value, safe and practical by large-sedan standards, so it’s a bit of a no-brainer.

But will buyers be quick to dismiss the new S6 sedan because it’s not a more practical SUV? Time will tell, but we hope not.

Does the new Audi S6 sedan represent the best mix of executive style and boy-racer performance? Tell us what you think in the comments below.

Mercedes’ homogenised design is a bit of a double-edged sword, and while the CLS does wear its styling confidently, it probably looks a little too much like the cheaper and much smaller CLA for our tastes.

Both are swoopy four-door coupes from Mercedes-Benz, so of course there will be some similarities, but keen-eyed car spotters will notice some differences.

While the proportions are similar, the longer wheelbase and bonnet line gives the CLS a more mature look, and the extra details found in the head- and tail-lights, and front bumper stand it apart.

The changes to the 2022 version also brings in AMG’s 'Panamericana' front grille, which adds a bit of welcome aggression to the front end.

From the side, the steeply raked roof flows seamlessly into the rear, while the 20-inch wheels fill out the arches well.

All four doors are also frameless, which is always cool to see.

From the rear, quad-exhaust tips hint at the CLS’s sporty intentions, while a prominent rear diffuser and subtle boot lid spoiler also feature.

Inside, the biggest change to the CLS is now the inclusion of the MBUX multimedia system, which keeps it in line with the E-Class, C-Class and other Mercedes models.

AMG sports seats are also fitted, wrapped in Nappa leather and 'Dinamica' fabric upholstery for all pews.

Our test car also came fitted with red contrast stitching and seat belts, adding a racy streak to the CLS cabin.

Have to point out the new steering wheel that comes with the 2022 CLS, though, which mirrors the tiller offered in the new E-Class, and is a step back in terms of functionality.

It looks premium enough thanks to its chunky leather-wrapped rim and gloss black dual-spoke design, but using the buttons, especially when on the move, is difficult and unergonomic.

This design is definitely function over form, and might need a few more revisions to get it right.

Overall, we’d say the CLS is a good-looking car, but does play it a bit too safe with its styling?

To these eyes, the new S6 sedan is very attractive, albeit not outlandish, in keeping with its executive focus.

Up front, the subtly aggressive S body kit immediately comes into frame, with the bumper sporting sinister-looking side air intakes.

And, of course, there’s Audi’s signature Singleframe, which is not only large and in charge, but also finished in gloss-black, like many of the S6 sedan’s exterior design elements.

Below the heavily creased bonnet, the HD Matrix LED headlights look both angry and sophisticated, with their integrated LED daytime running lights (DRLs) providing a crisp signature.

Around the side, the S6 sedan goes about its business quietly, but its blistered wheelarches do add some bulk and help to accentuate its strong shoulder line.

And then there are the thick skirts and 21-inch alloy wheels (with a space-saver spare), which have a sporty twin five-spoke design. It’s all very classy.

Speaking of which, the rear end is arguably the S6 sedan’s best angle thanks to its wicked LED tail-lights, which have a segmented signature.

The chunky bumper below incorporates a diffuser element that houses the quad exhaust tailpipes, while a blink-and-you’ll-miss-it bootlid spoiler rounds out the look.

Inside, the S6 sedan is a technological tour de force, with 10.1- and 8.6-inch touchscreens dominating its centre stack. The former is responsible for most of Audi’s latest multimedia system’s functions, while the latter takes care of the climate controls.

This set-up works pretty well, although a few too many taps are required for certain functions, and then there’s the issue of the glass display coverings, which are absolute fingerprint magnets alongside the gloss-black accents used throughout.

That said, the 12.3-inch digital instrument cluster and windshield-projected head-up display on hand are brilliant. In fact, they set the standard for the entire industry thanks to their design and breadth of functionality.

The S6 sedan does, of course, feel a little bit more special than the regular A6 inside, with the obvious additions being the front sports seats, which are covered in supple Valcona leather alongside the armrests. They even have diamond-stitched inserts.

Then there’s the obligatory flat-bottom steering wheel (with paddle-shifters), which is trimmed in Nappa leather alongside the gear selector, upper dashboard, door shoulders and knee rests. Indeed, hard plastics are hard to find here.

Meanwhile, a black headliner adds to the sportiness alongside the black Alcantara door inserts, but the cabin is otherwise a familiar (read: classy) affair.

Measuring 4994mm long, 1896mm wide, 1425mm tall and with a 2939mm wheelbase, the CLS slots neatly between the E-Class and S-Class in size and positioning.

Up front, occupants are afforded ample room for head, legs and shoulders, while the electronically adjustable seats make it easy to find a comfortable position.

The steering wheel also features a telescoping function – an always appreciated feature – and the expansive glasshouse makes things feel open and airy.

Storage options include a deep door pocket, a cubby found under the armrest, two cupholders and a smartphone tray with wireless charging capabilities.

It’s a different story in the second row, though, as the sloping roofline does noticeably eat away at headroom.

Don’t get me wrong, a six-foot-tall (183cm) adult can still slide in there fine, but the roof is dangerously close to the touching the top of the head.

Leg- and shoulder-room is pretty good in the outboard seats though, while the middle position is compromised by the intrusive transmission tunnel.

In the second row, passengers have access to a bottle holder in the door, a fold-down armrest with cupholders, backseat map pockets and two air vents.

Opening the boot reveals a cavity offering 490 litres of volume, with an aperture wide enough to fit golf clubs or luggage for a weekend getaway for four adults.

The rear seats also fold in a 40/20/40 split fashion, but Mercedes-Benz is yet to detail how much volume is on offer with the rear seats down. And as a traditional sedan, the CLS is less practical than the liftback Audi S7.

Measuring 4954mm long, 1886mm wide and 1446mm tall, the new S6 sedan is a large sedan in every sense of the term, which is mostly good news when it comes to practicality.

Cargo capacity is decent, at 520L, but can be increased to an undisclosed amount with the 40/20/40 split-fold rear bench stowed.

Speaking of the boot, there are four tie-down points and a cargo net to help secure loose loads, while a bag hook and a side storage net are also on hand, alongside a 12V power outlet. Bulkier items will, however, be confronted by a decent load lip.

In-cabin storage options are numerous, but not all are effective. The glovebox is well-sized, while the driver-side cubby is surprisingly large, but the central bin is shallow, mostly taken up by the wireless smartphone charger, two USB-A ports and the SD and SIM card readers.

A pair of cupholders is located in the centre console, with a 12V power outlet found in between, while the front door bins can accommodate one regular bottle each, just like their rear counterparts.

In the second row, there’s a fold-down armrest with two more cupholders as well as a shallow storage tray, while cargo nets are affixed to the front seat backrests.

The rear bench is pretty comfortable, with four inches of legroom available behind my 184cm driving position alongside decent toe-room. Headroom is also good, with about two inches on offer.

That said, three adults sitting abreast won’t enjoy the experience, due to the large transmission tunnel, which makes for limited footwell space. At least they’ll have access to a couple of USB-A ports and a 12V power outlet, below the central air vents.

For reference, child seats can be fitted to the outboard seats via top-tether and ISOFIX anchorage points.

The new S6 large sedan is priced from $149,900 plus on-road costs and is far better value than before, even if it does command a $33,900 premium over the regular A6's flagship variant.

Compared to its predecessor, the new S6 sedan is $21,480 cheaper, while Audi Australia claims it has also added $20,000 worth of kit.

Standard equipment not already mentioned includes metallic paintwork (our test vehicle was finished in Tango Red), dusk-sensing lights, rain-sensing windshield wipers, soft-close doors, auto-folding side mirrors with heating, rear privacy glass and a hands-free power-operated bootlid.

Inside, satellite navigation with live traffic, Android Auto and wireless Apple CarPlay support, digital radio, a 705W Bang & Olufsen 3D sound system with 16 speakers, a panoramic sunroof, keyless entry and start, power-adjustable front seats with heating, a power-adjustable steering column, four-zone climate control, an auto-dimming rearview mirror and LED ambient lighting feature.

Of note, buyers can opt for the $7700 Dynamic Package that bundles in speed-sensitive electric power steering, a rear limited-slip differential and all-wheel steering. It was not fitted to our test vehicle.

In terms of rivals, the BMW M550i sedan is identically priced, while the Mercedes-AMG E53 sedan is much more expensive, at $173,800. The S6 sedan arguably has the former beat on value but loses the performance battle due to its 390kW/750Nm 4.4-litre twin-turbo V8.

Powering the Mercedes-AMG CLS 53 is a 3.0-litre turbocharged inline six-cylinder engine, punching out 320kW/520Nm to all four wheels via a nine-speed automatic transmission and Merc's '4Matic+' AWD system.

A 48-volt mild-hybrid system, known as 'EQ Boost', is also fitted that serves up to 16kW/250Nm from take-off.

The result is a 0-100km/h acceleration time of 4.5 seconds, keeping it on pace with the likes of the 331kW/600Nm Audi S7 (4.6s) and 390kW/750Nm 250kW/500Nm BMW 840i Gran Coupe (5.2s).

While not as brutish as AMG’s eight-cylinder engine, the straight six strikes a great balance between pace and poise that perfectly suits a model like the CLS 53.

The new S6 sedan is powered by a hard-hitting 2.9-litre twin-turbo V6 petrol engine that produces a strong 331kW of power from 5700-6700rpm and a punchy 600Nm of torque from 1900-5000rpm.

Compared to its aforementioned predecessor, power is unchanged, while torque has increased by 50Nm.

This unit is mated to a 48V mild-hybrid system that includes a trick Electric-Powered Compressor (EPC), which helps to reduce its turbo lag.

A reliable eight-speed torque-converter automatic transmission is responsible for swapping gears, while drive is sent to all four wheels via Audi’s rear-biased quattro system.

This combination helps it sprint from a standstill to 100km/h in an impressive 4.5 seconds, while its top speed is electronically limited to 250km/h.

Official fuel consumption numbers for the CLS 53 are pegged at 9.2 litres per 100km, while we managed an average of 12.0L/100km in our launch drive.

All of our driving was relegated to country back roads and high-trafficked urban areas however, with no consistent freeway driving.

We’ll reserve judgement on how accurate the fuel economy figures are until after we’ve had the car for longer, but the EQ Boost system is designed to help keep consumption down by being able to coast the engine in particular situations.

The new S6 sedan’s fuel consumption on the combined-cycle test (ADR 81/02) is 8.4 litres per 100 kilometres, while claimed carbon dioxide emissions are 197 grams per kilometre. Both figures are pretty keen given the level of performance on offer.

Audi says the aforementioned 48V mild-hybrid system reduces fuel consumption by 0.4L/100km thanks to its coasting ability, which sees the engine turn off for up to 40 seconds between 55km/h and 160km/h. It also engages idle-stop from 22km/h.

In our real-world testing, we averaged 14.4L/100km over 100km of driving skewed towards country roads over city traffic, with limited highway time. It’s worth noting that my spirited driving inflated this result. That said, while its fuel consumption is not as bad as it appears, this is still a thirsty sedan.

For reference, the S6 sedan’s 73L fuel tank takes 98RON petrol at minimum.

There are certain expectations on a vehicle when it wears a Mercedes badge, namely it should be comfortable to drive while also dripping with the latest tech. And here the large four-door coupe delivers in spades.

Driving the car is smooth, easy and comfortable when in its default drive setting, you can really sink into the CLS and just eat up the miles in comfort.

There are small niggles, like the 20-inch wheels and low-profile tyres (245/35 front and 275/30 rear) throw up a bit too much road noise into the cabin, but for the most part, around town, the CLS is serene, supple and supremely soothing.

However, switch it over to Sport or Sport+ and the steering gets a bit heavier, the throttle response a bit sharper, and the suspension a bit stiffer.

Does it transform the CLS into a sports car? Not quite, but it certainly dials up driving engagement to a level where you can really have some fun.

Though this isn’t a full-fat AMG in the same vein as an E63 S and doesn’t feature the ubiquitous 4.0-litre twin-turbo V8, the CLS 53’s 3.0-litre six-cylinder engine is still plenty potent.

Coming away off the line feels particularly brisk, likely due to the EQ Boost system adding a bit of poke, and even flat-footing it mid-corner delivers a noticeable surge of urgency from the creamy straight six.

However, the best of the CLS 53 experience, in my opinion, is actually the sound, with the exhaust letting off the right sort of pops and crackles in Sport+ mode on overrun.

It’s rude and obnoxious, but also completely surprising coming from the motoring equivalent of a three-piece dress suit – and I love it!

The brakes are also up to task for scrubbing speed, but our relatively brief time with the car was in extremely wet conditions, so the 4Matic+ AWD system was hugely appreciated.

The S6 sedan has no right being this good in a straight line and around corners…

Much of its success is owed to the 2.9-litre twin-turbo V6, which is now one of my favourite engines being built today. Simply put, it absolutely hammers.

Punch the accelerator from a standing start and it doesn’t take long for 600Nm to be on tap all the way through, and just a little bit beyond, the mid-range.

Occupants are firmly pressed into their seats as the S6 sedan sprints towards the horizon with vigour. Soon enough, 331kW arrives and hangs around until just prior to the redline.

Needless to say, this acceleration is addictive, and the EPC deserves some of the credit, as it effectively mitigates any dreaded turbo lag and ensures the engine is always seemingly on boost.

But we also need to acknowledge the eight-speed torque-converter automatic, which is a real beauty. Gear changes are nice and smooth, which is great, but what’s even better is their relative quickness – dual-clutch transmissions be damned!

Of course, extra performance can be extracted by switching between the engine and transmissions’ settings but, rest assured, they both stand up, no matter what.

However, we’d suggest spending time in the former’s most aggressive setting, as it unleashes the sports exhaust system, which sounds unreal.

Upshift with intent and you’re met with a booming ‘brap’. Downshifts and the overrun will even gift you a series of pops. In fact, the S6 sedan soundtrack sounds strangely similar to that of the five-cylinder RS3, and we have absolutely no problem with that.

Better yet, the S6 sedan has an appetite for corners, with its neutral handling a standout, partly thanks to its hard-working rear-biased quattro all-wheel-drive system, which works in tandem with all the other electronics to ensure there is plenty of grip at any given time.

This controlled driving pleasure is enhanced by the electric power steering on hand, which has a variable ratio. At low speed, it’s nice and light, but those after more heft can always switch to another one of its settings, which become progressively heavier… arguably too heavy.

Feedback through the wheel is also good, while the steering itself is pretty direct, lending itself to sporty driving, which, of course, is half of the S6 sedan’s mantra.

Coming into corners, braking performance is solid, thanks to the massive 400mm front and 350mm rear discs with red callipers, so the driver is brimming with confidence at every turn, even though there’s an unladen weight (with 75kg driver and luggage) of 1985kg to manage.

But let’s not forget the S6 is an executive sedan, so it has to ride like one. Thankfully, it does. The independent five-link suspension has air springs and adaptive dampers, which serve up comfort in spades, especially at high speed.

Its firm tune does come into frame when travelling on unsealed or uneven roads, with this exacerbated by the large 21-inch alloy wheels, which have a penchant for catching sharp edges.

ANCAP awarded the A6 range (including S6) a maximum five-star safety rating in 2018.

Advanced driver-assist systems extend to autonomous emergency braking with pedestrian detection, lane-keep and steering assist, blind-spot monitoring, rear cross-traffic alert, adaptive cruise control with stop-and-go functionality, high-beam assist, driver attention alert, hill-start assist, tyre pressure monitoring, surround-view cameras and front and rear parking sensors. Yep, buyers aren’t left wanting here.

Other standard safety equipment includes six airbags (dual front, side and curtain), electronic stability and traction control systems, anti-skid brakes (ABS), brake assist and electronic brake-force distribution, among others.

Like all new Mercedes-Benz models sold in 2021, the CLS 53 comes with a five-year/unlimited kilometre warranty with roadside assist over that period.

This outclasses the assurance period offered by BMW, Porsche and Audi (three-year/unlimited kilometre), and matches that available from Jaguar, Genesis and Lexus, who recently upgraded their offering.

Scheduled service intervals are every 12 months or 25,000km, whichever occurs first.

The first three planned services will set buyers back $3150, broken down as $700, $1100 and $1350 apiece.

The S6 sedan comes with Audi Australia’s three-year/unlimited-kilometre warranty, which falls short of the premium market’s relatively new five-year standard that was set by Genesis and followed by Mercedes-Benz.

Three years of roadside assistance is also bundled in, although this term can be extended up to nine years if the vehicle is serviced at an authorised dealership, which is great.

Speaking of which, service intervals are every 12 months or 15,000km, whichever comes first. Capped-price servicing plans are available, costing $2350 for three years/45,000km or $4110 for five years/75,000km. They’re pricey, but you weren’t expecting the opposite.