Mercedes-Benz C43 vs Audi RS5

What's the difference?

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.

It's hard to look past the fact that the RS 5 Sportback is more than $50k more expensive than an S5 Sportback, which itself is hardly cheap. But is it the pick of the RS 4 and RS 5 family? Probably, but I’m personally still a sucker for the RS 4’s wagon shape

I also reckon it’s currently the pick of the three fast German options, and I love that you can get it in this bodystyle.

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

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.

From the B-pillar forward, the RS 5 Sportback is identical to the Coupe, with the same deep and aggressive front apron to set it aside from the lesser S5 and A5 models. The same applies at the rear, with a bespoke rear bumper with large oval exhaust outlets on either side.

It also scores the delightfully pumped wheelarches on each corner of its mechanical siblings, along with the same 20-inch wheels.

Like the coupe though, one detail that seems to be missing from the previous RS 5 is a significantly wider track. Compared with the S5 Sportback, the RS 5 Sportback’s track is just 11mm wider at the front and 20mm at the rear, so if you halve those figures per side they’re likely just from additional camber in the wheel alignment settings.

So those wheelarch blisters are largely for aesthetics, rather than a necessary adjustment to allow for a broader stance.

Enough of the comparisons though, the five-door liftback bodystyle gives it a uniquely sleek yet practical appearance, with all of the tasty performance cred of the coupe and wagon.

Also as I alluded before, BMW is unable to build you an M4 Gran Coupe, which would be its BMW equivalent, due to the regular Gran Coupe being built in a different factory to the 3 Series sedan and 4 Series coupe. And Mercedes-AMG’s C 63 bodystyle options are limited to sedan, coupe, wagon and convertible - there just isn’t a five-door liftback on the list.

The RS 5 Sportback’s interior is a continuation of the beautifully detailed coupe and wagon, with real carbon fibre, aluminium and leather tastefully applied leather that has a subtle edginess that really fits the Audi RS brand.

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.

This is where it’s hard not to make Goldilocks analogies. Where the RS 5 coupe has a decent boot with a small, sedan-like opening and a back seat for two that’s difficult to access via the front doors, the RS 4 has a great wagon boot with a huge opening and a back seat for three that’s easy to access because it has back doors.

The RS 5 Sportback is closer to the latter, but sacrifices the cargo height of the wagon and the sloping roofline will mean that taller passengers may want for more headroom and easier access to the back seat. It does retain the wagon’s third seating position back there though, and neither back seat compromise is an issue for my 172cm height.

Its 480 Litres VDA seats-up boot capacity is a match for the S5 Sportback, which is only 25 litres short of the RS 4. Like the S5, a space saver spare sits beneath the boot floor.

The RS 5 Sportback also ticks important convenience boxes like dual cup holders front and rear, bottle holders in each door, decent oddments storage and auxiliary connections front and rear, plus ISOFIX child seat mounts for both outward rear seat positions.

If you’ve ever found yourself perusing Audi’s mid-size RS line-up and been disappointed by the lack of back doors in anything without a wagon body, the RS 5 Sportback is the solution.

Two door coupes are a pain to live with unless you have no need for the back seat, and I’m led to believe that there are some who aren’t enchanted by the RS 4 Avant’s epic cool factor.

If this is you, and your local freeway onramp isn’t long enough to suit the S5 Sportback’s 4.7s 0-100km/h claim, you’ll also be delighted to know that the RS 5 Sportback is priced at the same $157,700 (before on roads) as the RS 5 Coupe, and $4800 above the RS 4. You won’t be as delighted by the $51,900 premium over the S5 Sportback.

The standard equipment is a match also, with the Quattro sport rear differential, RS sports exhaust and 'Dynamic Ride Control' with adaptive dampers all on the list.

You’ll also find the black 'Fine Nappa' leather sports seats with diamond stitching, Bang & Olufsen 3D audio, LED headlights, gloss black exterior details, panoramic sunroof and red brake calipers.

The Audi virtual cockpit driver display also features, plus RS-specific tyre pressure, torque and g-force readouts and a shift light.

The RS 5 Sportback aligns with the MY19 RS 5 coupe spec upgrade, which brings a head-up display, wireless phone charger and USB outlets for rear passengers.

The RS 5-exclusive 'Sonoma Green' paint seen on the coupe is also now available on the Sportback for the same extra $1950 any colour aside from Nardo grey will add to the sticker price.

One detail you don’t get on the coupe is the auto liftback with gesture control, similar to the RS 4’s tailgate.

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.

The RS 5 Sportback is a genuine mechanical match for the coupe and RS 4, which means the same and impressive 331kW/600Nm 2.9-litre twin-turbo V6 and delightfully adaptive eight-speed ZF torque converter auto.

Max power is available from 5700-6700rom, while peak torque is accessible all the way from 1900-5000rpm.

The Quattro all-wheel drive system retains it 60 per cent native torque bias for more of a rear-drive dynamic. 

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.

Given the familiarity of the RS 5 Sportback’s mechanical package, there’s also no surprises with its fuel consumption.

The official combined fuel consumption figure is 8.9L/100km, which is 0.1 more than the coupe, and the same as the RS 4.

We managed a rare feat during our 350-plus kilometre drive taking the back way from Canberra to Goulburn, to Oberon, then to Bathurst via Lithgow, where we managed to match the official combined figure on the car’s trip computer.

While it’s a good rule of thumb that you can do this on a steady motorway cruise, it was mighty impressive to do it along the flowing country route with regular climbs and overtaking.

It is worth noting though that like all RS models, the RS 5 Sportback commands expensive 98 RON Premium unleaded as a minimum.

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.

There’s a good chance you’ve skipped straight to this point, and if you've driven the excellent RS 5 Coupe or the RS 4 you won’t find any surprises in the RS 5 Sportback. This is a very good thing.

Compared to its muscular looks, its general refinement around town is still a really nice surprise for a car of this performance calbre. It’s not hard to imagine driving your grandmother around in comfort. In fact, she would have been right at home on our 350-plus kilometre country cruise between Canberra and Bathurst. 

You might miss the V8 growl from an AMG, but the V6 does make a nice bark once you give it some decent throttle, and it delivers those 331kW and 600Nm very effectively through those two turbos. As I often find myself saying these days, this thing is so easy to drive so fast!

Its very impressive 3.9 second 0-100km/h claim feels entirely realistic, which matches the coupe and trumps the RS 4 by two tenths.

You probably won’t be surprised to hear that the ZF eight speed torque converter auto feels right at home with the RS5, being smooth as around town, and as responsive and quick to shift as you’d ever want it to be when you’re getting up it.

Its overall refinement does mean it’s not quite as exciting to drive fast as the AMGs or BMW Ms, even with the controls and mechanicals tightened up in Dynamic mode.

Our best opportunity to put it through its performance paces was via the surprise set of bends hidden between Bathurst and Sofala, where it simply honked its way uphill. You instantly forget that it's a rather large five seater with almost room for a pony in the boot. There’s miles of grip, it steers really nicely and the big brakes do a really good job under pressure. This, is a proper RS.

While not specifically stated, the RS 5 Sportback should be covered by the same five-star ANCAP safety rating as the rest of the fixed-roof A5 family. Note that this rating was awarded based on older 2015 criteria though.

It matches the RS 5’s impressive list of standard safety features, which includes front city AEB with pedestrian detection.

Interestingly, the initial Sportbacks being delivered to Australia match the six airbag count of the coupe, which covers front and side airbags for the driver and passenger, along with curtain airbags covering the front and rear.

The second batch and all future RS 5 Sportback examples will match the eight airbag count of the wagon, which adds rear side airbags to the list above. If you’re about to place an order, I’d strongly recommend insisting on the eight airbag version that this score is based on.

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.

Like all Audis, the new RS 5 Sportback is covered by a three year, unlimited kilometre warranty. This is short of the five year-plus periods that now form the status quo among mainstream brands, but equal to the terms offered by BMW and Mercedes-Benz. Lexus differs by offering a four year, 100,000km plan. 

RS 5 Sportback service intervals are a generous 12 month/15,000km though. 

Another detail to be aware of is that RS models are still exempt from Audi’s Service Plan Pricing capped price servicing plan.