BMW 320d vs Mercedes-Benz C300

What's the difference?

Despite BMW's wholehearted embrace of the SUV its 3 Series is still a critically important model for the brand in Australia. And this new version certainly has the spec and tech to take the fight up to Merc's C-Class. And if you're in the happy position of making that choice, it's now a whole lot harder. For our money the 330i marks the sweet spot with extra performance, safety tech and standard features for only a fraction more than $3k over the 320d entry-point.

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.

At just over 4.7m nose-to-tail the new 3 Series has crept 76mm in overall length but that dimension is still more than 200mm shy of its next-size-up 5 Series sibling.

Changes to the exterior design are more evolutionary than revolutionary. You're never going to mistake this car for anything other than a BMW 3 Series.

But even if the face is familiar, aerodynamic efficiency is outstanding. BMW admits its claimed Cd of 0.23 was achieved with a base model running on 17-inch wheels (not offered here), but even if bigger rims knock a few fractions off that number it's still an amazing result for a conventional four door sedan.

Big contributors are a full width front spoiler, 'air curtains' managing flow around each corner of the nose, almost complete sealing of the largest areas underneath the car, and a functional rear diffuser section.

The signature kidney grille has grown and is delivered as a single piece, with active shutters incorporated to manage cooling air flow through to the engine. Twin adaptive LED headlights (standard on all models) feature a sharp notch on their lower edge, a big clue for new model spotters.

Broad, carefully managed surfaces characterise the bonnet and flanks of the car, with a distinct character line just above door handle height enhancing its confident stance.

The slightly smoked L-shaped LED tail-lights sit proud of the body, and 18-inch alloys are standard on the 320d, stepping up to 19s on the 330i.

The interior has been redesigned with revised controls and new materials, including slick 'aluminium teragon' finish on the console and dash in the M Sport.

As you can see in our interior images, it's been tidied up and simplified considerably, although it will still be instantly recognised by current BMW drivers.

Highlights are a 12.3-inch configurable digital 'Live Cockpit Professional' instrument display (lifted directly from the X5), a new 10.25-inch media touchscreen and a standard (larger) head-up display.

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!

A longer wheelbase (+41mm) has helped increase overall cabin space and rear room specifically.

There's plenty of storage provided with a large lidded box between the front seats as well as two large size cupholders in a recessed section in front of the gear shift (which can be closed off with a roll-top style cover).

The glove box is large and there are big bins in the doors with separate holders for full-size bottles.

Rear legroom is generous. At 183cm, sitting behind my own driving position, there was plenty of fresh air between knees and seatback, with lots of foot room to boot.

Headroom was more marginal with a straight back leading to a bonce/roof interface. But there are adjustable rear vents, twin cupholders in a fold-down centre armrest, and big bottle holders in the doors. Multiple USB ports (Type A and Type C) and a 12-volt power outlet are provided front and rear.

The boot space offers up a 480-litre luggage capacity with a 40/20/40 split-folding rear seat increasing cargo flexibility. Local towing capacity is yet to be confirmed, but indicative (European) ratings for both models are 750kg for an unbraked trailer and 1600kg braked.

Standard rubber is run-flat so there's no spare of any description.

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.

Initially, there are two sedan versions of the new W206 series C-Class on offer – the base C200 from $78,900 before on-road costs, and the more-powerful C300 grade from just over $90,400 before ORC.

There's no sugar coating this. These prices represent a shocking $12,000 and $15,100 jump, respectively, over the outgoing W205 equivalents. Which means that, now, even the cheapest C-Class costs significantly more than any of its corresponding direct rivals.

For example, the Audi A4 35TFSI kicks off from $59,900, Volvo S60 B5 Inscription AWD from $62,490, Genesis G70 2.0T from $63,000, Alfa Romeo Giulia Sport from $63,950 and BMW 320i Sport Collection from $69,900 (drive-away). And even the Tesla Model 3 Standard Range (SR) Plus RWD and Polestar 2 SR EVs slip in at under $60K apiece. All before ORCs, BMW-aside.

But the news isn't all bad, because even though prices have jumped, Mercedes reckons it gives you more, as well as the very latest in technology, design and engineering, since the W206 is the newest kid on the block by some margin.

Let's begin with equipment levels.

On top of the front electric seats, satellite navigation, automatic parking, dual-zone climate control, artificial leather Mercedes brands ARTICO, digital radio, remote boot lid closing and 18-inch alloys that the base C200 all came with previously, the new one now adds an AMG Line body kit and interior trim, adaptive cruise control, Lane Keep assist, a 360º camera, auto high-beam headlights and keyless entry/start. These go a long way to offset that $12,000 price hike.

Plus, for the first time, you'll also score a centre airbag between the front seats, fingerprint scanner ID tech for the new 11.9-inch media display and a 48V mild-hybrid system to help cut fuel consumption and emissions. Most of these items are segment-firsts. Note, too, that the engine's been downsized from 2.0 litres to 1.5L. More on that later.

Meanwhile, the C300 gains all of the gear above, as well as a new 2.0L mild-hybrid engine, leather trim, privacy glass and a Driver Assistance Package Plus – a very worthwhile addition since it brings Active Blind Spot Assist, Active Brake Assist with Cross-Traffic Function, Active Emergency Stop Assist and Active Lane Keeping Assist, among heaps more driver-assist safety features.

More details follow in the Safety section below.

Of course, these are just the start of a wave of fresh C-Class models. Soon they'll be joined by the AMG 43 and thunderous AMG 63 sports sedans, as well as plug-in hybrid versions.

So, from a pricing perspective, yes, the new C-Class sedan does come at a premium compared to its direct competitors. But all that kit – including the advanced hybridised and safety technologies that are now either standard or available – presents a compelling value proposition.

Especially as the W206 sedan is measurably larger and thus roomier than before.

The 320d is powered by a 2.0-litre four-cylinder twin-turbo-diesel, featuring common-rail direct-injection and variable inlet timing. It produces 140kW at 4000rpm and 400Nm between 1750-2500rpm.

The turbo's multi-stage design incorporates a small, high-pressure, fixed-vane turbocharger as well as a larger, low-pressure, variable-vane turbo to maximise response, performance and efficiency.

A 2.0-litre single turbo-petrol four-cylinder engine sits under the 330i's bonnet incorporating direct-injection, as well as variable valve and cam timing. Peak outputs are 190kW from 5000-6500rpm and 400Nm between 1550-4400rpm.

Mark the date because this is the first time the BMW 3 Series has been offered in Australia without a manual gearbox option. Both launch models send drive to the rear wheels via an eight-speed automatic (with wheel-mounted shift paddles) only.

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.

Despite each car's performance potential claimed fuel economy for the combined (ADR 81/02 - urban, extra-urban) cycle is commendably low.

BMW says the 320d delivers excellent diesel fuel economy, consuming a miserly 4.5L/100km, emitting 119g/km of CO2 in the process, with the 330i's fuel consumption figure coming in at 6.4L/100km and 147g/km.

You'll need minimum 95 RON premium unleaded in the 330i, with both petrol and diesel requiring 59 litres to fill the tank to full capacity.

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.

First, the performance figures. BMW claims the 320d will accelerate from 0-100km/h in 6.8sec, which is agreeably quick, while the 330i knocks that down to 5.8sec, which is properly fast.

Both engines deliver the same 400Nm of maximum torque at low rpm; 1750-2500rpm for the 320d, and a broader 1550-4400rpm spread for the 330i. Mid-range acceleration is strong and satisfyingly linear in each, the 330i that bit more urgent at the top end.

The eight-speed auto is velvety smooth, with the wheel-mounted shift paddles on hand for rapid 'manual' changes. Engine noise is muted at low revs but nice and rorty under pressure.

A stated aim in the development of this 3 Series was "dynamic engagement", and the standard strut front, multi-link rear suspension has been tuned to reinforce the driving part of the brand's long-standing 'ultimate driving machine' promise.

The standard suspension includes tricky two-stage dampers front and rear, but with all cars at the local launch fitted with the optional active damper system we'll have to wait to report on its quality (or otherwise).

This car's centre-of-gravity is 10mm lower than the model it replaces, which may not sound like much, but in engineering terms, absolutely is. In concert with a perfect 50:50 front-to-rear weight distribution, and wider tracks front and rear, it helps deliver an overall planted feel and predictable cornering balance.

The electro-mechanically assisted steering is accurate and linear with good road feel, which is not always the case in recent Beamers.

The launch fleet was also rolling on 19-inch rims (standard on 330i, optional on 320d) shod with Bridgestone Turanza run-flat rubber (225/40f - 255/35r) and despite that type of tyre's reputation for harsh characteristics and a moderate level of road noise, ride comfort on the typically coarse rural roads we covered in the Victorian high country was impressive.

Braking on both models is by ventilated disc front and rear, and even in spirited cornering maintained their power and efficiency. The M Sport brake package fitted to the 330i dials things up with four-piston alloy calipers (sourced from Brembo) up front.

The standard sports steering wheel is fat and grippy, the sports front seats combine firm location with long-distance comfort and overall noise levels are low. Overall, this is a super-impressive touring car.

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.

The W206 C-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.

To that end, there are now 10 airbags fitted, including dual-front combined pelvic/thorax airbags, front centre airbag, rear side airbags, window airbags and driver's knee airbag.

Plus, you'll find Autonomous Emergency Braking front and rear (including for cyclists and pedestrians, at speeds from 7km/h to over 200km/h), adaptive cruise control with active stop/go, a 360 degree camera, Active Parking Assist, drowsy driver monitor, Active Lane Keeping Assist, Blind Spot Assist, ABS anti-lock brakes with Brake Assist, Adaptive Brakes with Hold function, brake drying and Hill Start Assist, electronic stability control, traction control, dusk-sensing LED lights, rain-sensing wipers and runflat tyres with tyre pressure warning.

The C300, meanwhile, adds Driving Assistance Package Plus, with features such as Active Blind Spot Assist, Active Brake Assist with Cross-Traffic Function, Active Emergency Stop Assist, Active Lane Change Assist, Active Lane Keeping Assist, Active Steering Assist, and Active Stop-and-Go Assist… basically, this is where the car actually intervenes to help avoid accidents and impacts. There's also the PRE-SAFE side accident anticipation and protection system.

Both models also feature two ISOFIX child seat restraints as well as three top tethers for straps.

BMW offers a three year/unlimited km warranty, which is drifting off the pace now with the majority of mainstream brands stepping up to five-year cover, with some at seven.

On the upside, bodywork is covered for 12 years, the paint for three, and 24-hour roadside assistance is complimentary for three years.

Servicing is condition based, so the car tells you when maintenance is required, and BMW offers a range of service packages in 'Basic' and 'Plus' grades up to 10 years/200,000km.

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.