Audi RS4 vs Mercedes-Benz CLA-Class

What's the difference?

Practicality, performance and polish, all in one very handsome wagon shape. The Audi RS4 Avant is welcome reminder of the days before SUVs ruled the world, and it leaves you wondering how we ever allowed that take-over to happen at all.

The new AMG C 43 may lack the drama and excitement we’ve come to expect from the German performance brand, but that doesn’t mean it’s a bad car. Yes, it could be more extroverted and the ride could be improved, but this is still a sharp-looking sports sedan with loads of punch.

This is a car that speaks to its times, with ever-stricter emissions regulations making it harder and harder for car companies to produce loud, wild and charismatic cars. So Mercedes-AMG has worked within those boundaries and come up with a car that retains at least some of those core elements that has made the brand so desirable over the years.

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

I think it looks fantastic; a tough, low-slung performance wagon that makes you long for the days when SUVs were only for people who wanted to climb mountains, not driveways. 

Looking at it straight-on, the Audi RS4 Avant looks wide and mean, with its blacked-out mesh grille that's kind of folded in the middle, giving it a sharp ridge that juts out in front of it. Interestingly, Audi's Single Frame Grille treatment is now a kind of no-frame grille, with the body colour extending all the way to beginning of the meshing.

Those 20-inch alloys perfectly fill the swollen wheel arches, with the red of the massive brake calipers peeking out from behind the spokes, while at the rear, two massive exhaust exits frame the rear end. 

Inside, it's a blacked-out, leather-wrapped space that feels both tech-savvy and well constructed. There's ridged leather on the seats, and a satisfying chunkiness to both the flat-bottomed steering wheel and the sizeable gear shifter. 

I've heard people complain about the positioning of the 10.1-inch centre screen, perched as it is above the dash a little like an afterthought, but I really don't mind it. Its big, clear, and positioned where it is, easy to both read and reach.

Mercedes has created something of a problem for itself with its decision to introduce AMG styling packages for the majority of its range, including the C-Class.

It means the C 43 has to walk a fine line between looking like a unique AMG model, rather than just a C300 with a bodykit and not out-doing the C63.

To that end it has AMG’s now familiar grille with vertical bars, the unique and complex-looking 20-inch alloy rims and a small lip spoiler on the boot. But otherwise it is surprisingly understated for an AMG, lacking the more obvious and muscular stance of previous AMG offerings.

Inside, there’s a similar theme, with the typical Mercedes-Benz luxury appointments but with a sportier, AMG twist. The steering wheel is chunky and comes with AMG branding, metallic shift paddles and a pair of rotary dials/buttons that allow you to alter the various drive modes and settings.

The one on the right allows you to switch between the pre-set Comfort, Sport, Sport+ and Individual modes, while the one on the left can scroll between the various individual aspects to tailor the settings to the conditions.

In typical modern fashion the design is tech-laden, with a digital display for the instrument panel (that can be switched between various graphics) and a large, tablet-style central multimedia touchscreen that controls the majority of the car’s non-driving functions.

Ah, the practicality of a wagon, remember that? Honestly, I'm sometimes surprised that SUVs have managed such a hostile takeover, especially when I climb out of a well-sorted estate, like the RS4 Avant.

It measures 4782mm in length, 1866mm in width, and 1438mm in height, making it slightly longer - but much lower - than the Audi Q5.

But while Audi's SUV manages a commendable 463L of luggage space with the rear seats in place, the RS4 Avant delivers 495L, with the that number swelling to 1495L with the second row folded flat.

The point is, it delivers the perks of a sizeable SUV, without ever feeling so big. 

Up front, riders will share cupholders, bottle holders in the doors, and multiple USB and power connection point, along with storage cubbies of various sizes and shapes. 

In the back, rear seat riders get the same premium interior treatment as the driver, and get their own air vents with digital climate controls, bottle holders in their doors, USB connection points, and ISOFIX attachment points at each of the window seats in the back. 

The new C-Class has grown slightly in size compared to the model it replaces, most notably with a 26mm increase in the wheelbase which you can feel in the cabin.

The front seat space is good, with excellent adjustability for the power-adjustable seats and steering column. I had no trouble finding my ideal seating position which makes for a more enjoyable and uncompromised driving experience.

Rear space is a bit tighter (which is typical for this segment/size of vehicle), but thankfully the standard seats do have very deep sculpting in the backs which allow for more knee space and foot room.

However, at approximately 180cm (six-foot), I wouldn’t like to sit behind my seating position for long periods as my knees were touching the seat back, and headroom is compromised with the panoramic glass roof.

In terms of small item storage there’s a lidded console box in between the front seats as well as a pair of cupholders and a small tray where you can place your mobile phone.

It’s worth noting, though, that early examples of the C 43 in Australia do not have a wireless smartphone charging pad, with that reportedly being introduced from February production.

While that’s good news, it’s not really competitive in this day and age to offer a car costing six-figures without such technology.

There’s also only a single USB-C power outlet in the front, which is another disappointment, but there is a pair in the back.

Mercedes does win some points back for a respectable 455-litre boot, which has a nice wide load opening that will make packing luggage easier.

We’ll get to the major change under the bonnet shortly, but another significant alteration for this latest C 43 is the price.

It now starts at $134,900 (plus on-road costs), which pushes it well above its market rivals, the BMW M340i xDrive and Audi S4, which start at $104,900 and $106,200, respectively.

However, Mercedes has added more technology under the bonnet and loaded the C 43 up with standard equipment, including its '4Matic' all-wheel drive system, adaptive damping, rear-wheel steering and 20-inch alloy wheels.

In terms of creature comforts, the C 43 is well-appointed, with leather upholstery, a head-up display, augmented reality navigation, a panoramic sliding sunroof, and a Burmester 3D surround sound system.

There are two option packages for the C 43. The 'Digital Light Package' costs $2400 and adds Multibeam LED headlights with 'Ultra Range' highbeam, 'Adaptive Highbeam Assist Plus' as well as active light function and cornering light function.

The 'Performance Ergonomics Package' includes AMG Performance front seats, an AMG Performance steering wheel in Nappa leather and microfibre and the 'AMG Track Pace' system for an additional $5200.

It's a beast of a power plant - a twin-turbo 2.9-litre six-cylinder TFSI that will deliver 331kW at 5700rpm and 600Nm at 1900rpm, sending it thundering to all four wheels (because quattro) via an eight-speed tiptronic automatic.

That's enough, says Audi, to deliver a 0-100km/h sprint time of 4.1 seconds, which is plenty quick. 

The biggest talking point about this new car is the engine, with AMG downsizing from the old C 43’s six-cylinder to a 2.0-litre four-cylinder turbocharged petrol engine.

But it’s not just any turbocharged four-pot, because it is fitted with technology that Mercedes claims has been inspired directly from its Formula One team.

While the F1 team engine facility is based in England, this engine was designed and developed by the Mercedes-AMG team at its Affalterbach headquarters, but the concept of the electric turbocharger reportedly comes from the engine that powered Lewis Hamilton to multiple world championships.

The electric exhaust gas turbocharger - to give it its official name - uses a small electric motor on the turbocharger shaft to spin up the blades without having to wait for any exhaust gases to pass through it first.

To power the electric turbo the C 43 is equipped with a mild-hybrid 48-volt electrical system.

Mercedes claims this means reduced lag and improved throttle response for a sportier driving experience. 

It also helps make this small engine produce big amounts of performance, with AMG extracting 300kW of power and 500Nm of torque from this 2.0-litre, which is more power than the previous six-cylinder C 43 managed.

The engine is paired to a nine-speed multi-clutch transmission, which isn’t a dual-clutch with a pair of clutches operating on every second gear ratio, but instead uses a “wet start-off clutch” for better take-offs and smoother shifting on the move (at least in theory).

Power is sent to the road via all four wheels thanks to Mercedes’ 4Matic all-wheel drive system.

Audi says you'll get 9.5L/100km on the combined cycle, and emit 218g/km of CO2. But not if you drive it like you'll want to drive it. Get a little too familiar with the accelerator and you can expect that number to climb.

The RS4 Avant is fitted with a 58-litre fuel tank.

Despite the smaller engine you can hardly call the C 43 miserly, with a claimed combined urban/highway cycle rating of 9.1-litres per 100km. That’s only a 0.2L/100km improvement over the old six-cylinder.

On test, which included a return trip from Sydney to Bathurst via motorways and some dynamic back road driving, we saw a return of 11.8L/100km on the car's onboard computer.

While hardly hybrid-worrying, it’s impressive to think that driven modestly, such a potent engine can return a single-digit fuel figure.

It's a thundercat, the RS4 Avant, and might well be among the world's most undercover sleepers, given its ability to deliver near-supercar pace from its fairly understated station wagon body shape. 

Sink into the driver's seat, grip the chunky, leather-wrapped steering wheel and kick over the engine, and the low rumble of then exhaust immediately informs you that you're in something with some serious performance potential.

The acceleration is properly addictive, with the RS4 piling on speed on the exit of corners, shrinking the gap between bends so much that you're hurriedly standing on the brakes again as you barrel into the next turn before you know it.

It feels properly, properly sporty, and you can't help but feel a little smug about the fact you can effectively pour an entire Bunnings into the massive boot, where people in true supercars are lucky if they can fit even fit themselves in them. 

And I think that's the magic of a car like this, that straddles that line between practical and potent with such aplomb, it feels like it you're not making much in the way of sacrifices, and you can knock off the school run or a hill sprint with equal ability.

Downsides? Well, even in its angriest settings, the gearbox felt a little fidgety at pace, shifting up or down at strange moments on the way into or out of corners. You can take control via the paddle shifters, of course, but it wasn't the most intuitive gearbox I've experienced. The steering, too, felt a little - and I  mean a little - disconnected, even in its sportiest settings.

Let’s start with the good news. The new Mercedes-AMG C 43 is a quick car. The engine may be small in size but the electric turbocharger does its thing and provides plenty of punch.

You can get a performance boost, too, thanks to the belt-driven starter generator, which acts as a mild hybrid and gives you a surge of 10kW for a brief period if you need a sudden burst of extra speed.

The chassis is well-sorted, too, at least from a dynamic point-of-view. The rear-wheel steering can provide up to 2.5 degrees of turning, which improves handling at speed and manoeuvrability when parking.

However, there are some less-impressive elements to the C 43, too. The obvious one is the drama, or rather the lack thereof.

As I said at the beginning, the C 43 has never been as wild or raucous as the V8-powered C 63, but when you buy an AMG there’s a rightful expectation that it will provide some thrills.

The C 43 simply doesn’t have that character about it. Yes, it’s fast, but it produces that speed with efficiency rather than excitement.

And it’s not an engine size problem, because even the 2.0-litre four-cylinder A 35 and CLA 35 offer more ‘wow factor’ than the C 43.

Yes, the engine makes noise under acceleration (and it can be altered between discreet and sporty) but even at its best it sounds muted and lacks the evocative tone of a V8 or six-cylinder engine. 

Another disappointment is the transmission calibration, with the gearbox awkwardly shifting out of first gear on multiple occasions during our test drive.

In the taller gears it felt smooth enough cruising along, but given its low speed shifts we’d like to spend more time in the urban environment before passing final judgement. 

The other notable element of the driving experience we struggled with was the ride quality. While fine on the smoother motorways, our test drive included time on some patchy country back roads and the C 43, even in the ‘Comfort’ suspension setting, was simply too firm.

Riding on low profile tyres, the adaptive dampers struggled to isolate the cabin from the imperfections in the road, leading to a fussy ride at times.

Overall the C 43 is a good car, but it feels like there are still some areas where Mercedes could improve it to make it really live up to the AMG badge.

The C43 gets a comprehensive list of safety equipment that leaves little out. Obviously there are the usual passive safety items, like 10 airbags, including dual-front combined pelvic/thorax airbags and a front centre bag that drops between the front seat passengers to minimise the chances of a head clash.

Also included as standard is autonomous emergency braking front and rear (covering speeds between 7.0-200km/h), adaptive cruise control with active stop/go, a 360-degree parking camera, 'Active Parking Assist', 'Active Lane Keeping Assist', 'Blind Spot Assist' and, of course, anti-lock brakes with 'Brake Assist' and 'Adaptive Brakes' with Hold function and electronic stability control.

Also included are dusk-sensing LED lights, rain-sensing wipers and run-flat tyres with tyre pressure warning.

The C43 also comes equipped with Mercedes’ 'Driving Assistance Package Plus', which adds even more safety gear. This includes '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'.

While the C43 hasn’t been specifically crash-tested, the latest C-Class was rated by ANCAP with a five-star score for all models except the upcoming C 63 S E Performance.

Audi vehicles are covered by a three-year, unlimited-kilometre warranty, which is feeling more than a little underdone when compared to some competitors.

Services are due every 12 months or 15,000kms, and Audi allows you to pre-pay your service costs for the first five years, at a cost of $3,050.

The C 43 is covered by Mercedes’ five-year, unlimited kilometre warranty, which has become the new standard for the luxury car market.

Service intervals for the car are at 12 months/25,000km, which is on par with industry standard.

Mercedes-Benz Australia will offer a service plan for the C 43, prices were yet to be confirmed at the time of publication but the company has indicated it will be similar to the C300. 

That means $550 for year one, $900 for year two, the third service costs $1000 and the fourth year service costs $2450 - for a total of $4900 for the first four years of ownership.