Mercedes-Benz C300 vs Mercedes-Benz CLS350

What's the difference?

Over five decades, the Mercedes-Benz C-Class has pivoted between mastery and mediocrity, and all-too-often relied on that three-pointed star up front to win over buyers.

Thankfully, the W206 is one is one of the better generations. It's easier on the eye, comfier to travel in, more intuitive to use, safer across the board and a huge improvement to drive. On the evidence of the C200 and C300 launch grades, there's newfound depth and consistency to savour.

Sure, prices have gone up, the C200 could use a bit more power, the steering could benefit from a bit more feel, the odd build-quality glitch made itself heard and there's a fair bit of road noise at times, but overall, the C-Class now deserves to be at the top of your luxury medium sedan shopping list.

Particularly if you can afford to stretch to the rorty C300.

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.

If you're checking out the new C-Class for the first time from the front, you'll probably think… hmm, it looks just like the old one, and that's largely true.

But a side view reveals proportions that have changed significantly, thanks to the more raked windscreen, shorter overhangs and cleaner lines, which give it a slightly smaller S-Class look.

Which is more in fitting with where Mercedes wants to place this car against its 3 Series and A4 competitors.

Additionally, the taillights are split for the first time, allowing for a wider boot aperture since the lid now contains some of the lighting elements.

The shrunken limo looks aren't just the whim of some designer or Mercedes-Benz marketing department copywriter, either.

Underneath is an albeit highly modified version of the latest S-Class' MRA2 platform, which results in the longest (at 4755mm) and widest (at 1820mm) C-Class in the series' 40-year existence, as well as the first with this level of electrification capability.

Height and wheelbase dimensions also see a stretch, by 8mm and 25mm to 1450mm and 2865mm over the previous model respectively, and to the benefit of passenger accommodation.

Speaking of which, get used to this new interior aesthetic and general layout – it's a look that's probably going to filter through to most coming non-EQ-branded Mercedes models over the next few years.

From S to C to future E and A classes and beyond. It's a rare instance of trickle-down economics actually working!

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'.

One of the best things about the new C-Class is that it's larger and therefore roomier than before. It's also higher quality, easier to use, more comfortable to sit in and - overall - more of a delight to behold.

In contrast, the old C-Class dash looked and felt like it was designed for a much cheaper car, especially compared to Audi's efforts.

Obviously related to the S-Class this time around, it's clear Tesla provided the inspiration for the twin floating screen look and layout, which are just right in their driver orientation and ease of functionality.

There's never really been anything wrong with Mercedes' old front seats, but these AMG Line items are both sumptuous and bracing, keeping their occupants well located ahead of the clever and thoughtfully laid out dashboard.

The brilliantly high-resolution MBUX multimedia and voice-recognition system now works as it should - intuitively and logically, with the screen menus simple to recognise and easy to use, and most without the need to get lost in confusing sub-menus. Just like BMW has managed for years.

If you want to change the instrumentation design, it's now a couple of clearly marked steps, using handily placed switchgear. The same goes for the superb climate control and audio systems. And the wireless Apple CarPlay/Android Auto connected faultlessly and worked a treat. Effortless see-and-push operation all round, backed by concise and classy graphics.

No more degree in Earth-to-Mercedes comm skills required to master this C-Class interior.

Yet there's just enough old-school Benz features to appeal to brand diehards, from the eternal door-card mounted electric seat controls and column-mounted gear shifter, to the deep centre console and turbine face-level air vents. They meld together beautifully with the advanced tech also on offer, like the optional augmented-reality head-up display with 3D-graphics.

Annoyingly, on one of our test cars, that tradition also extended to a couple of squeaks and rattles, proving that maybe Mercedes hasn't quite conquered all its past quality gremlins. And, like most luxury cars nowadays, endless ambient lighting choices are available of dubious taste.

Never mind. This is the finest C-Class front-seat environment since, well, probably the original W210 190E's of the 1980s.

And all those extra dimensions pay dividends in terms of interior space in the back seat.

There's plenty of knee room even with the tester sat behind their 178cm frame; head room is adequate even with the optional sunroof fitted, and there's ample shoulder space. So, it's more comfortable than any C-Class ever has been in terms of sheer dimensions.

Additionally, the rear backrest is well angled, while the cushion is deep enough to provide sufficient thigh support. But the centre perch is a bit of a squeeze for all concerned. Best avoided.

There's also added practicality to be found with the large and deep door pockets, front seat-back map pockets and folding centre armrest, that not only has a tablet holder, but when pressed in twice, also reveals sliding cupholders as well. Clever.

The C-Class rear seat is really lacking for nothing, with face-level air vents, overhead lighting, grab handles and coat hooks all highlighting the level of thought that went into making this a practical compact family sedan.

Plus, the C-Class comes with this folding ski port, which along with the folding rear seats, increases boot volume from 455L to, well, a lot more. While that's not quite as good as others like the BMW 3 Series, it's big enough for this car.

Note that there is no spare wheel, as the tyres are of the limited-distance runflat variety.

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.

Probably the biggest departure compared to any previous C-Class is this generation's switch to direct-injection four-cylinder-only powertrains – including the coming Mercedes-AMG high-performance versions. Now that should be interesting.

As mentioned earlier, the C200's four-cylinder turbo engine is now about 25 per cent smaller in capacity, down from 2.0L to a 1496cc 1.5L twin-cam 16-valve turbo engine. Dubbed the M254, it pumps out 150kW of power at a high 6100rpm and 300Nm of torque between 1800-4000rpm.

That's not to say it's lacking in muscle, though, since it can sprint from zero to 100km/h in 7.3 seconds, on the way to a 245km/h top speed. These outputs are at least a match for the bigger-engined 3 Series and A4 equivalents, by the way.

If it's more you want, then the C300 features a 1999cc 2.0L turbo version of the M254, delivering 190kW at 5800rpm and 400Nm between 2000-3200rpm. This slashes that 0-100km/h time to a speedy six seconds flat. There's also an extra 20kW of overboost available for short periods if you're really in a hurry, while - where legal - it's possible to hit 250km/h.

Both send drive to the rear wheels via a nine-speed torque-converter automatic transmission, while the 48V mild-hybrid system, dubbed EQ Boost, employs an integrated starter-generator and lithium-ion battery that provides an additional 15kW and 200Nm of electric boost at low engine speeds.

So, while it doesn't ever run purely on electricity, the electrification tech certainly either brings more punch or takes the load off the petrol engine, depending on how you're driving it.

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.

Remember when I said that the C-Class moved to an all-four-cylinder engine range? Well, that's primarily to help it better meet fuel consumption, efficiency and lower emission targets.

On the Australian combined fuel consumption cycle, the C200 manages 6.9 litres per 100km – and that's extremely impressive for a medium-sized sedan weighing almost 1.8 tonnes. So is the fact that the larger-engined C300 returns only 0.4L/100km more at 7.3L/100km. Fitted with a 66-litre tank, these numbers suggest that the former can average nearly 960km between refills while the latter can manage just over 900km.

These figures translate to averages of 157 and 164 grams per kilometre of carbon dioxide emissions respectively. On the flipside, both these Euro-6 emissions rated engines require 98 RON premium unleaded petrol to deliver their best.

So much for lab tests. Out in the real world, we drove both cars for several hundred kilometres on a hot summer's day, from inner Melbourne during peak-hour traffic, to some great curvy rounds out in central Victoria, featuring some tight corners and ample opportunity to really stretch both cars' legs.

Over these routes, we averaged an indicated 8.4L/100km in the C200 and – astonishingly – 7.4L/100km in the C300. Yes, the larger and more powerful engine proved more economical.

Clearly, along with the advanced aerodynamics, engine stop/start system and 48V mild-hybrid tech, all that downsizing works. No wonder Mercedes deemed it unnecessary to bother with diesel engines for this generation C-Class.

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.

There has been a philosophical shift in how the C-Class is presented.

Even with their standard-in-Australia AMG Line package, the regular grades like the C200 and C300 are now leaning into the brand's luxury heritage, while the BMW-baiting sports sedan versions will be left to the coming AMG versions.

And this in turn profoundly informs how the W206 drives.

Even with the optional Sports Pack on 19-inch wheels, the C200 as tested finally feels like a premium midsized sedan experience. Muted at start up, the 150kW/300Nm 1.5L turbo steps off the line smartly and smoothly, its nine-speed auto shifting effortlessly through the gears to keep the engine feeling lively and lusty.

Around town it's easy to mistake the engine as a larger-capacity unit, since throttle response is instantaneous, with little to no lag detectable. It's a strong start for a base powertrain, especially as the C200 settles into a relaxed cruise at freeway speeds. Cycling through the driving settings also reveals how feisty the 'Sport' mode is.

But the 1.5L's lack of size becomes obvious the moment you need to overtake quickly, or when a quick squirt of acceleration up a hill is required, because the engine needs plenty of revs to approach that 6100rpm power peak. While still pretty brisk in these situations, it's also fairly vocal too, with a sense of having to work hard to maintain momentum.

Switching to the C300 highlights how much better suited the 190kW/400Nm 2.0L turbo is to highway driving, leaping forward with much more force and conviction, across the entire performance spectrum. In every metric, this is a better choice – throttle response, mechanical refinement, cruising ease. And the fact that the onboard computer showed less fuel consumption cements our preference for the larger-hearted C-Class.

In fact, both models possess a chassis that feels like it could do with a whole lot more power. Light and tight around town, the steering weighs up nicely at higher speeds, with a linear and reassuringly planted feel. The same also applies to how confident and controlled the Mercedes feels through fast, tight turns, yet settles into a relaxed and comfortable tourer along long, straight stretches of road.

It's a pity, then, that such dynamic agility and prowess doesn't really involve the driver, since the steering feels quite isolated from what's going on underneath; for the vast majority of C-Class buyers, that's fine. But, as a quick spin in any latest BMW 3 Series or Jaguar XE will reveal, there isn't an intimate, two-way connection going on here. That's probably going to be reserved for the AMG models.

Our C200 rode on bigger wheels and steel springs, while the C300 was fitted with optional adaptive dampers. In the previous-generation C-Class, the differences would be stark: a busy and jittery ride in the former, compared to soft yet still unsettled suspension in the latter.

That's all ancient history now, as even the 'passively' suspended C200 now isolates its occupants from the rough and tumble of our inconsistent roads. Still firmish, but no longer harsh.

And the C300 with adaptive dampers seems downright plush by comparison, while offering the driver personalisation options within the aforementioned driving models to tailor the steering, performance and engine sound settings that best suit the prevailing mood.

Too bad there's some road and tyre noise intrusion heard inside when driving over coarse bitumen roads. This is a common pitfall amongst German vehicles in Australia.

Still, it doesn't detract from the fact that the whole chassis set-up can at-last cushion and cosset occupants like, well, a mini S-Class.

Which is the whole point of the W206 C-Class. It now majors on comfort and reassurance like the better Mercedes-Benz models used to, while still being suave and sprightly enough to be a memorable – if not over-exciting – drive.

As a result, the C300 especially is a much-more likeable car than past iterations. Just remember to tick the adaptive damper option for the most optimal experience. Job well done, Mercedes.

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.

Kudos to Mercedes-Benz for being the first luxury manufacturer in Australia to offer a five-year/unlimited kilometre warranty – matching most other mainstream makers. Lexus and Audi have only recently followed suit.

A five-year roadside assistance subscription is also included. Service intervals are 12-monthly or at every 25,000km, whichever occur first.

Additionally, a four-year capped price service plan is available, at $550 for the first year, $900 for the second, $1000 for the third and $2450 for the fourth, totalling $4900.

Alternatively, buyers can also choose three pre-purchase service plans to save a bit of money, but these must be bought prior to the first service.

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.