BMW 840I vs Mercedes-Benz CLS350

What's the difference?

If you’re the sort of buyer who wants a car that signifies a lifestyle that is ‘large and in charge’, the BMW M850i Gran Coupe could be just the thing for you. It isn’t as showy as some of its competitors, and mightn’t reach the same levels of excitement as those cars either - but it is a convincing offering in its own right, and a beautiful piece of design at that. 

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.

This could be BMW’s most convincing design in years. I mean, the X5 is predictably handsome, the X3 was unexpectedly muscled, and the less said about the frumpy 1 Series and busy 3 Series (apart from the wagon… drool) the better.

To my untrained but enthusiastic eye, the 8 Series Coupe is a bit too rounded over its rear haunches, and the rear screen is just a little steep - to me, that lets its dimensions down a little. But this. This is gorgeous. 

I mean, you might have questions over the tail-light design, which is a theme across a few BMW models now. But there isn’t as much confrontation between horizontal and vertical graphics for this model as you’ll find one other big Bimmers, like the X7. 

The M850i model has BMW Laserlight headlights, which throw a sharp beam and look menacing in their signature, while the grille and bumper are strong. The stance of the car is prominent - there’s a long body, a long wheelbase, and a long body in general. The standard wheel package consists of 20-inch rims, and they don’t look disarmingly large.

As our images show, there’s a lot to talk about when it comes interior design and finishes, but the cabin doesn’t quite benefit quite as mochas you might think it would from all that real estate. I mean, with dimensions of 5074mm long (on a 3023mm wheelbase), 1932mm wide and 1402mm tall, this is a squat, yet substantial vehicle. It’s just more cramped than you’d think inside.

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'.

I recall a Mitsubishi designer telling me, once upon a time, that he dreamed of making ‘a big car on the outside with a very small interior’. Maybe he made the jump to BMW, because that’s pretty much the 8 Series Gran Coupe.

There aren’t many other vehicles on the market, of this size, that offer less space inside. The boot capacity, for instance, is just 440 litres. Competitors like the Audi A7 (535L) and Mercedes CLS (520L) easily outdo it - but at least this car has more boot than the Panamera (405L), though the BMW is a smidge bigger. The cargo space is large enough for a couple of overnight suitcases, but you’re hardly going to fit a family of four’s luggage for a week away. 

And while we’re in the “not quite what you’d expect” column, the back seat space is hardly commodious. There’s enough space for me, at 182cm, to sit behind my own driving position, but not without wishing for a bit more toeroom, headroom and knee space. 

The big centre console section eats into the space in the rear, justifying the brand’s “4+1” seating claim, and unpleasantly it has a hard plastic finish to rest your leg against. Getting in and out of the second row isn’t easy for bigger people, and it’s quite a squat down into the rear seat - it really has taken inspiration from its squashy-back-seated predecessor in that regard.

If you have smaller rear-seat occupants, however, there will be catered for with dual ISOFIX and three top-tether points, plus there are air vents with climate controls (quad zone in total), and two USB-C ports as well. There are sun-blinds on the rear windows, too, which is a plus, and there is a pair of cup holders in the fold-down armrest, and map pockets in the seat backs, too. The door pockets are near-useless, though.

The front seats score better practicality, with bottle holders in the doors, bigger and sturdier cup holders, a covered centre storage bin between the seats with a USB-C port, and a wireless phone charger (Qi) with standard USB port in front of the gear selector.

Above that is the weird, very out-of-place quick buttons (1-8) that BMW could easily do away with, and further up are the controls for the climate control (thankfully with hard buttons for fan speed and temperature), and above that is the media screen, a familiar looking 10.25-inch touch display running BMW OS 7.0. 

The screen is quick and crisp, and is backed up by the rotary controller and buttons on in the centre console area. There’s wireless Apple CarPlay (now at no cost for three years), as well as a built-in SIM card for 4G data and access to the BMW Online news and weather stations, accessed through the screen.  

It’s all pretty easy to use, and the sound system is excellent - the standard setup consists of 16 speakers, with DAB+ digital radio, Bluetooth and USB plus the smartphone mirroring tech, provided you don’t have an Android device, as Android Auto is still missing from BMW’s range.

It’s a nice cabin, but I couldn’t help but thinking that I’d want a little more differentiation from the lesser models in the range if I was spending this much. Especially considering the optional cost of the interior trim fitted to our test car - see below for more detail.

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.

Benz has dropped the 250d grade, which means you can no longer have your CLS with a diesel engine. That also means the new entry fee is higher with the CLS 350 kicking the line-up off at $136,900 (list price).

You’ll be rewarded with a decent amount of equipment for the outlay, though. Coming standard on the CLS 350 are those two 12.3-inch screens, a head-up display, a 13-speaker Burmester stereo, sat nav, Apple CarPlay and Android Auto, digital radio, surround view camera, leather upholstery, heated front seats, 'Brown Ash' wood trim on the centre console, wheel-mounted shifting paddles, AMG exterior and interior packages, auto-parking, 20-inch AMG wheels, air suspension, proximity key and privacy glass.

The CLS 450 4Matic lists for $155,529 and adds air filtering in the cabin, power closing doors, a sports exhaust system and all-wheel drive.

At the top of the three-grade range is the Mercedes-AMG CLS 53 4Matic+ for $179,529. The extra money buys you nappa leather upholstery, wireless charging, the ‘Night’ body kit, an AMG exhaust system, and of course, a lot more grunt which you can read about below.

If you’re going for the M850i, you’re getting the big bopper engine. It’s a 4.4-litre twin-turbo V8 petrol engine, and it isn’t short on horsepower.

The outputs for this engine are 390kW of power (at 6000rpm) and 750Nm of torque (from 1800-4600rpm). Hardly numbers to sneeze at.

And the performance figures are exceptional, too: the claimed 0-100 km/h time is just 3.9 seconds. That’s because there’s the traction of BMW’s xDrive all-wheel drive system, and shifting gears is an eight-speed automatic transmission.  

For what it’s worth, your humble reviewer saw a 0-100km/h time very close to that (4.2sec). 

The quoted kerb weight for this model is 1995kg.

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.

You can’t really expect a big V8 beast like this to be a fuel miser, and it isn’t.

The claimed consumption is 10.7 litres per 100 kilometres. Which is alright, honestly, given the sheer volume of car you’re driving. 

But on my test - which consisted of more than 300km of mixed driving, including days of city commuting, some twisty mountain driving, and all the freeway floundering to get there - I saw an at the pump real-world figure of 15.4L/100km.

That’s not very efficient, and it’ll be expensive to run on the daily — yet the argument could be made that if you’re spending this much on a car, fuel costs won’t matter much to you. But with a small fuel tank capacity of 68 litres, it could become a little inconvenient as you’ll be seeing a lot of your local servo.

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.

It’s an impressive thing, this M850i xDrive Gran Coupe. But I’m just not sure who it’s trying to please.

It’s not the sort of German monster coupe-sedan that grabs you by the scruff of the neck and throws you around with its mammoth acceleration. Not unless you poke it and prod it and make it really angry.

And that might be exactly what you want to do - put it in Sport mode, sling the shifter across to sport or manual mode, hear the exhaust open up from a pursed-lip tongue-click to an open-mouth growl. 

You’ll push hard on the accelerator, watch the tacho needle jolt to the redline, and if you’re in auto mode you’ll feel the transmission whipcrack as it shifts rapidly up through the gears as you’re shoved back into your seat. Before you know it you’ll be in licence-loss zone, and you won’t have even made the tyres chirp - that’s how immense the traction from the all-wheel drive system is.

You’ll brake hard into a sharp bend, and you’ll feel the front end dip and the body of the car change direction more readily than you’d think given its size as you turn in. The steering response will meet your expectation, with rapid reaction to adjustments mid corner. And the Active Roll stabilisation system will mean you’re not being thrown around in your seat, because it’s sitting flatter and truer than you might have expected - you’ll notice how it works extremely well in conjunction with the car’s torque-vectoring-by-braking system. There’ll be little weight shift or body roll to be counteracted, and that’ll inspire you to push it even harder.

Put it in manual transmission mode and you’ll rejoice that it won’t overrule you and shift up, but you’ll also feel shortchanged because it gets to the end of its limit very quickly. And when it hits redline, it emits a breathless little cough rather than a “oh maybe I should stop” rev-bounce noise.

But, if you’re like me, you might be doing all this with a niggling thought in the back of your mind that, while this car is technically really good and it’s a clinical performance car, you might just think to yourself, “I’m not having as much fun as I thought I would”.

A Mercedes-AMG would be more fun; it’d be more raucous, more of a muscle car experience. An Audi RS7 (at least the previous one) would be noisier, brasher, more theatrical than this car. And likewise, a Porsche Panamera - no matter the model you go for - would be more entertaining in the bends.  

Maybe it’s just a bit too predictable - and maybe that’s a result of this car being honed for drivers who will spend more time on the Autobahn than anywhere else. I have to say, there are much, much worse (and slower) ways of getting from A to B, and the highway cruising comfort of the M850i Gran Coupe was what impressed me most. 

It’s also surprisingly adept at urban driving duties, coping well with unpleasant city surfaces, though potholes can still upset things because of the stiff-sidewalled run-flat tyres. The suspension does an exceptional job otherwise, however, and I switched between the Adaptive drive mode and Comfort mode for my commuting duties. Both proved comfortable and controlled.

The M850i is by no means a failure when it comes to fulfilling the expectations you might have of a luxury sports sedan of this size. In fact, it’s close to a distinction. But I just can’t help thinking that it’s not as much an ‘M car’ as that M850i badge might have you believe it should be.

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.

The second generation CLS was never crash tested and this new one has yet to be as well. So, while it hasn’t been given an ANCAP star rating, given it shares so much with the five-star rated E-Class we’d expect it to score nothing less than that, too.

Along with nine airbags, ABS, and traction and stability control the level of advanced safety equipment onboard the new CLS is seriously impressive. There’s the 'Driving Assistance package Plus' which brings AEB with cross traffic function, evasive steering, blind spot warning with an active function and lane keeping assistance.

For child seats you’ll find two ISOFIX mounts and three top ether anchor points.

BMW backs its cars in Australia with a three-year/unlimited kilometre warranty.

You may be confused if you head to the BMW site and see that M models and 8 Series models aren’t covered by BMW’s pre-pay capped price servicing plan (as I saw when testing this car), but CarsGuide can confirm that the 8 Series is indeed covered - unless it’s the real M8, not this M850i jigger. 

BMW Australia has clarified that the Service Inclusive pack for five years/80,000km of maintenance cover is $2490 for Basic cover (no brakes/pads, no wiper replacement), or $5641 for the more comprehensive Plus pack. Hardly affordable, but nor’s the car. 

The company uses a condition-based servicing program, too - there are no set service intervals, but the car will tell you when it needs maintenance based on how you drive it.

For what it’s worth, we ran the numbers on resale value using Glass’s Guide predictive analysis tool, and after three years/40,000km the expected retained value for this version is approximately 66 per cent - which is impressive.

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.