Mercedes-Benz C300 vs Lexus RX350

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 RX is a big SUV that doesn't always look, or drive, like one, and – in 500h guise especially – can put a smile on a driver's face, too.

Gone are the cabin quirks and the polarising design elements (well, mostly...), and in their place you'll find a solid, premium-feeling family offering without much in the way of drawbacks.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

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!

Honestly, the Lexus RX looks far more powerful, and cohesive, in the metal than it does in some photos, and in the right colour (we're fond on the deep black or the copper-rose hues), it looks downright fetching.

That Predator-shaped front-end is massive, but the way the Spindle grille kind of bleeds in the body work at the nose of the vehicle is a neat trick, and the whole design ethos gives the RX a sportier, more modern, and more intimidating, energy from almost every angle.

Perhaps the most clever element though is the wave-like design piece that links the rear window with the boot, somehow managing to shrink almost-five-metre SUV (visually, at least), and leaving the RX looking more sporty than hulking.

The door handles are cool, too. They’re fixed, and you just touch them to open the door, with a similar system used once inside to get out again.

Inside, Lexus has gone for a clean, modern-feeling space, and, thankfully, there isn't a Remote Touch trackpad in sight. Instead, you can choose between two screen sizes – 9.8- or 14.0-inch – which kind of dominate the dash, while the air-con controls are digital and interactive, too.

It must be said, though, some interior treatments feel far more special than others, and while Lexus in Australia isn't spilling on specifics for our market just yet, the top-spec models will almost certainly feel more plush than the cheaper ones.

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.

The entire RX range now rides on Lexus' GA-K platform, which is lighter (-40kg), more rigid, and offers a lower centre of gravity (-15mm) than the model it replaces.

The RX is wider (+25mm to 1920mm), lower (-10mm to 1695mm), but no longer (still 4890mm) than the outgoing model. But Lexus has lengthened the wheelbase (+60mm to 2850mm) to earn some extra backseat space for rear riders.

And it must be said, there is lots of room for backseat riders. Sitting behind my own 175cm driving position I had more than enough knee room, and enough head room, and a general feeling of airy spaciousness.

Elsewhere you get the usual practicality perks, with two cupholders up front, two more in the pull-down seat divider that splits the rear seat, and there are two ISOFIX attachment points in the back seat, too.

Charging is handled by a four USB ports, and depending on the trim/spec balance Lexus in Australia shoots for, you should at least find vents with temp controls for backseat riders, too.

Lexus is yet to confirm the luggage space specs for the new RX, but given it’s only being offered with five seats, and that there’s been no change to the vehicle’s length, you can expect a fair bit of room for bags in its auto-opening boot.

This is an arbitrary seven out of 10, here. Because we don't yet know how many trim levels the new RX will launch in, how much each will cost, or what you'll get for your investment.

What we do know is that the RX will launch with three powertrain options: an all-new turbocharged hybrid, a second, more conventional hybrid, and a turbo-petrol engine. There’s a plug-in hybrid version available overseas, but we ain’t getting it. Or at least, not yet.

In terms of specific trims and equipment levels, you’ll need to wait until closer to the RX’s launch in early 2023 for the full skinny. But you can expect a choice between a 9.8-inch or 14.0-inch central touchscreen with wireless Apple CarPlay and Android Auto, an eLatch door system with fixed handles that unlatch at the push of button inside and out, as well as more high-tech safety kit (thanks to Lexus Safety System 3.0) than you can shake a radar at.

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.

Let’s start with what we’re not getting at launch. Internationally, there's a new plug-in hybrid variant that pairs a 227kW hybrid system with a 18.1kWh lithium-ion battery for an EV driving range of more than 65kms, but fight though Lexus in Australia did, it couldn't secure the model for our market at launch. It wants it though, and badly. So watch this space. 

Instead we get three options, including the RX 350h, which pairs a 2.5-litre petrol engine with Lexus' existing hybrid system to produce a total 180kW and 316Nm. It's paired with a constantly variable transmission and will be offered in two- or all-wheel drive.

There’s also a turbocharged 2.4-litre petrol engine on offer in the RX 350, good for 205kW and 430Nm, and paired with an eight speed automatic and AWD.

But the powertrain I really, really like lives in the RX 500h F Performance, and pairs a 2.4-litre turbocharged petrol engine with an electric motor up front, and a second at the rear axle, for a total of 273kW and 551Nm.

The all-new hybrid system has been designed with turbocharged engines in mind, and features a single electric motor at the front, and a bigger rear motor, with the latter able to provide real driving power to the rear tyres - and contribute to a sprint to 100km/h of just 5.9secs.

Lexus calls it an 'eAxle' motor, and it can deliver some 76kW to the rear tyres. It pairs with a 'DIRECT4' all-wheel drive system which the brand says improves "handling, controllability, and feel."

Fitting, then, that it features on the RX 500h F Performance, which also introduces a new go-fast tier for the Lexus brand (though one you can expect to see more frequently in the near future), and which sits between the existing F Sport and the top-tier, full-fat F models.

The brand says things like bigger brakes, performance components and the highest power outputs will be reserved for the F Performance models. And so it is with the RX 500h F Performance, which welcomes six-piston front brakes, adaptive variable suspension, dynamic rear steering and 21-inch wheels.

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.

Let’s start with the pure-petrol RX 350, which will sip a claimed 8.8 litres per hundred kilometres on the combined cycle, and will demand premium petrol. The RX 350h is more fuel efficient, demanding 6.4 to 6.7 litres per hundred kilometres on the combined cycle.

But the most impressive is the RX 500h, which Lexus says will need 8.2 to 8.5 litres per hundred kilometres — making it more efficient than the petrol-powered RX 350, despite producing an extra 68 kilowatts of power and 121 newton metres of torque.

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.

Right, let’s cut to the chase here. I like the way the all-new RX family drives, pretty much across the board. If that’s all the information you want or need, feel free to check out here and move on to the next sub-heading.

Still here? Ok, then let’s go a little deeper.

None of the powertrains on offer feel under-powered in the RX range, which is a good start, but they all do their jobs a little differently. 

The RX 350 is probably the most familiar, with a traditional automatic and that well-known petrol-powered punch. It’s not the most powerful engine on offer here, but it’s more than enough to get the RX up and moving — but, for mine, it can feel a little thrashy (or like it’s straining a little too hard), when you really start to push it, but such is the price you pay for a four-cylinder engine pushing a large SUV.

Next up is the RX 350h, which Lexus reckons will be the best-selling model in Australia. Lexus and Toyota have been doing hybrid powertrains for some time now, and the system fitted to the new RX is predictably solid-feeling, though it too has its drawbacks – namely that the constantly variable transmission can drone on and on under constant acceleration, and even the commendably insulated cabin can’t block it out completely.

So if this is a Goldilocks’ scenario, then the just right has to be the RX 500h, which blends its powerful powertrain with a traditional-feeling automatic to deliver plenty of performance and a tight, engaging drive experience that makes it feel as though the big SUV is somehow shrinking around you from behind the wheel, courtesy of the best performance kit (brakes, adaptive suspension, etc).

But to be honest, no matter the RX, the thing that really stands out here is its on-road dynamics. The car doesn’t really wobble about, there’s not much in the way of body roll, and it feels tight and confidence inspiring, no matter the model - but especially the rear-wheel-steering equipped 500h.

The RX also does a commendable job of locking the outside world outside of the cabin. Where you want it to be a calm and sedate family hauler, it can be that. But it can also put a smile on your face on the right road, too.

And that, I think, is something to be celebrated. And also not something we’ve come to associate with Lexus over the years. But that’s now beginning to change. Long live F Sport Performance, then.

The Lexus RX welcomes the brand's Lexus Safety System 3.0 setup, which means more high-tech kit than you can shake a radar at.

What appears where on the Australian lineup remains to be seen, but internationally the RX will offer things like Advanced Park, remote parking from your smart phone, Safe Exit Assist that will actually prevent you opening the doors should the cameras detect pedestrians or cyclists, and Pre-Crash Safety, which scans intersections for bikes, people or cars, and activate alarms and the brakes should it sense a collision.

That, and things like Front Cross-Traffic Alert, active cruise, Lane Departure Warning and Lane Tracing Assist, road-sign recognition and Lane Change Assist, should see Lexus shooting for a five-star ANCAP safety rating.

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 Lexus family is covered by a five-year, unlimited-kilometre warranty, which is about bang-on in the premium-vehicle space. 

While servicing details are yet to be confirmed, the previous RX required a trip to the service centre every 12 months or 15,000kms, and it will fall under the brand’s capped-price servicing program, and the Lexus Encore program, which offers all sorts of perks to owners.