Mercedes-Benz CLS-Class vs BMW 6 Series

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?

This isn't a car for everyone's tastes, but if you fit in to the buyer group that just doesn't really know what they want in a luxury car, it could be the perfect fit for your family. The 6 Series GT is a practical large prestige car, albeit one that will likely find very few buyers.

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?

There is no denying the 6 Series GT looks better than the old 5 Series GT. It isn't as frumpy, it looks more sporty, and to me it appears to have grown into its identity with more conviction than its predecessor.

That said, I don't necessarily like the look very much - it's a bit like a BMW X6 that has been rounded off a little and lowered down substantially. But I can appreciate some of the finer design aesthetics that it offers up: the frameless windows are a nice touch, and the swooping roofline looks smoother than a duck's back.

Other things like the active grille shutters and the air breathers ahead of the front doors are nice functional touches, and to my eye it lives up to BMW's hope of it looking "smooth but muscular". You can get the 630i with either the M Sport package, like you see here, or the more sedate Luxury Line, which is, well, more luxurious looking.

The M Sport styling and equipment package you see in the images here - with M aero kit and 19-inch wheels (ours had been upgraded to optional 20s) - help out with the athletic look of this very big vehicle.

It's huge in fact. The length of the 630i is 5091mm long, it measures 1902mm wide and sits at 1538mm tall, with a lengthy 3070mm wheelbase.

All that equates to a lot of room in the cabin, and what a sumptuous and delightful place it is to be - leather, wood and plush finishes abound.

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.

Now, I said before that this is a bit like an X6, but it has heaps better interior space than that SUV.

As soon as you slide into the driver's seat, you feel like your inside a large car. The cabin space is plentiful, and there's an abundance of storage on offer, too: there's a split-lid armrest between the seats, a pair of cupholders, a phone storage nook with wireless charging, and big door pockets with bottle holsters.

In the back you have access to door pockets, a flip-down armrest with cupholders (that middle part of the seat can fold down completely to allow storage of longer items), and there's excellent room on offer. How many seats in the BMW 6 Series GT? Five - like, five full-size seats.

Because the roofline doesn't rake as sharply as a four-door 'coupe', headroom is excellent for adults (even of the 183cm variety, like myself), and legroom and toe room are equally very good. This is bigger in the back than a 5 Series, but maybe not as plush as a 7 Series… so I guess it makes sense numerically for its nomenclature.

Of course you get climate control in the front (and in the rear if you option it), and the materials are excellent. The media screen is tablet-style, proudly displaying 10.25 inches of high-def real estate that is both touch-capacitive and controllable by way of the central rotary controller with touchpad. And get this - you can even use gestures to control certain elements like volume, swiping and changing tracks… but you have to option that.

The fully digital instrument display is bordered by a set of incomplete dial rings, which is just odd. BMW, back yourself - your buyers can handle just having a digital screen in front of them, particularly when it's as good as this one.

This grandiose hatchback's boot is commodious - with the back seats in place it has a huge 610 litres of cargo capacity, which extends to 1800L with the 40/20/40 seats folded down using the quick release levers in the boot area.

There is no spare wheel (the BMW range is fitted with run-flat tyres) but it does have a secondary hidden storage area under the boot floor for hiding items or stowing wet gear, bathers/swimmers or muddy clothes.

For context, the X6 has 580L seats up, 1525L seats down.

The BMW 6 Series Gran Turismo range starts off with the model tested here, the 630i. It has a list price of $123,500 before on-road costs - and that's whether you buy the M Sport Line or the Luxury Line.

That's quite a lot of money. And while it has a lot of equipment to help justify the cost, the smarter dollars will probably find their way to a more affordable 5 Series.

Standard gear in this spec includes adaptive air suspension with multiple drive modes, a colour head-up display, semi-autonomous parking, adaptive cruise control with steering assistance, auto high-beam LED headlights with LED daytime running lights, DAB+ digital radio, a 16-speaker harman/kardon sound system, a 12.3-inch driver information screen and a 10.25-inch media display with sat nav, Bluetooth and 'BMW ConnectedDrive' online services.

Hey, you even get a panoramic sunroof as standard! Plus there are things like an active rear spoiler, two USB ports and four 12-volt outlets, leather trim, heated front electric seats, electric steering wheel adjustment, keyless entry, push-button start, and an automatic boot.

It also comes loaded with active safety assistance functions - we'll get to that in the safety section below.

Things it's missing at this price point? Well, heated seats are an option, but bundled nicely into the 'Comfort Package' ($3000) which was fitted to our car. The pack includes heated seats front and rear, quad-zone climate control, electric sunblinds for the rear side windows, and electric seat back adjustment. Oh, and BMW continues to gouge consumers $623 for Apple CarPlay (which seemingly didn't work in our car).

The only other 6 Series GT model available is the 640i xDrive, which is again available with the choice of M Sport or Luxury body styling. It's also pretty exxy, with a list price of $148,900, but gets a more performance-focused drivetrain, as well as extra equipment: essentially the Comfort package, plus vented front seats, interior fragrance (eight options), memory settings for the front seats, 20-inch wheels and metallic paint.

Plus the 640i has Sport+ settings - it's probably the wrong car for those - and 'Integral Active Steering' to couple with the all-wheel drive system.

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.

Under the bonnet of the 630i is a 2.0-litre four-cylinder turbocharged petrol engine, which produces 190kW of power (at 6500rpm) and 400Nm of torque (from 1550-4400rpm). It uses an eight-speed automatic transmission, and is rear-wheel drive.

That may not seem a lot considering the size of this machine, but consider that some of the steamiest four-cylinder hot hatches have nearly the same outputs, and you realise this engine offers up a far-from slouched approach to propulsion.

The 640i xDrive has a 3.0-litre six-cylinder turbocharged engine with 250kW of power and 450Nm of torque. It gets the same eight-speed auto, but as the xDrive naming indicates, it's all-wheel drive.

But this is the one you'd prefer if you want to hit highway speed in a hurry - the 0-100km/h claim is 5.3 seconds, where the 630i takes a full second longer (6.3sec) according to the company.

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.

BMW claims fuel use of 7.0 litres per 100 kilometres, and you'll need to use 95RON premium unleaded when you fill up.

On my trip with the car, I saw about 9.0L/100km across mostly high-speed driving - some freeway, some highway, some country back road touring, and quite a bit of corners and city stuff thrown in as well. I think that's pretty respectable.

What wasn't so great was the lack of premium fuel in some of the 'away from civilisation' places on my route home. Keep that in mind if planning your own GT long-distance cruise.

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.

I'll put this out there - if you like to drive, there are BMW models for less than this one that will put a much bigger smile on your face. Like, a 440i Gran Coupe, or even just a 330i sedan…

But if you're in BMW's target market - that being older executive buyers who want space and luxury as a priority over thrills at the wheel, you could do a lot worse.

That's because the 6 Series GT lopes along the highway without fuss - the engine easily coping with the demands of overtaking moves, the adjustable drive modes allowing a light steering and wafting suspension feel to wile away the kilometres.

There are 'Comfort' and 'Comfort Plus' modes, but the latter is a bit too spongy and can be boaty feeling. The Comfort setting is made for the highway.

It is actually pretty agile for its dimensions.

If you decide to deviate from the straight sections, you'll be able to explore a little bit of dynamic range, especially when you dial up the 'Sport' mode, which changes the damper settings, steering weight, throttle and transmission response, and even the digital dials in front of the driver to a more aggressive look.

Our car had the 'Integral Active Steering' setting, which is a variable ratio steering system that includes rear steering - that essentially helps make is more turnable in corners at highway speed, and easier to park at lower speeds. It's difficult to say whether the assistance is excellent or not short of driving a car without the tech, but to this tester it was hard to hide the size and weight (1835kg kerb weight) of the vehicle.

That isn't to say it's clumsy or lumbering - it is actually pretty agile for its dimensions, though it makes a lot more sense on long drives and coastal cruises than it does in the narrow and twisty alpine roads of the Snowy Mountains Highway that I tested it on.

There's good grip from the tyres, and strong response from the powertrain - but if it were my money, and I had to have a 6 Series for whatever reason, I'd be looking towards the 640i model, which has a thumping six-cylinder with 250kW/450Nm - certainly an engine that would be more at home in this car. Plus that model comes with AWD.

The BMW 6 Series GT range has a five-star Euro NCAP crash test score based on 2017 testing, but it hasn't been scored by ANCAP.

There's the usual array of airbags - dual front, front side, full-length curtain and driver's knee airbags are included, plus parking sensors all around, and heaps of safety tech including the 'Driving Assistant Plus' package with lane departure warning and lane keeping assist, forward collision warning, auto emergency braking (AEB) front and rear, blind-spot monitoring and rear cross-traffic alert, and adaptive cruise control with stop and go.

That's all great stuff, and so is the 360-degree camera system with adaptive display - so, if you're reversing and you turn the wheel to one side, the image on screen will move, too. It'll also go between a birds-eye view and a backing-up perspective, and that can take some getting used to.

What was less convincing in terms of the user experience was the rear auto braking, which seemed to be scared of the car's own shadow. On multiple occasions the car jammed on the brakes when reversing out of driveways on to empty streets - be it in the normal height, or the raised height setting.

The 6 Series GT has dual ISOFIX anchor points and three top-tether points are there and ready for baby seats or child seats.

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.

BMW runs a condition-based servicing plan, which means the car will tell you when it needs servicing. But you can rest assured it won't (theoretically) cost you much, with the brand's 'Service Inclusive' pack. It covers you for basic maintenance as and when required for five years/80,000km. According to BMW, that includes "annual vehicle checks, oil changes, all filters, spark plugs and labour costs for the duration of the package".

BMW offers a three-year/unlimited kilometre warranty plan, and you get the same cover for roadside assistance.