Audi RS 4 Avant v Mercedes-AMG C 63 S Estate 2018 Comparison

The Audi RS 4 Avant and Mercedes-AMG C 63 S Estate are two cars that prove you don’t have to compromise on space when it comes to performance.

They also stand square against the raft of performance SUVs being foisted upon family buyers in the race to put a premium face on high-riding family utility vehicles.
While they may not offer the rugged off-road capabilities alluded to by SUVs, both the Audi and Mercedes-AMG wagons on test offer similar levels of space and practicality; but because they are cars they simply drive better.

With a lower centre of gravity and heaps of muscle, they each more than meet the handling and grunt requirement for drivers looking for some punch from their family haulers.

The Audi RS 4 Avant has been updated for 2018 with a new 2.9-litre twin-turbocharged V6 at the heart of the changes. The new engine replaces Audi’s rambunctious 4.2-litre V8 and proves there is a replacement for cubic displacement, the 2018 Audi RS 4 Avant is quicker than its predecessor, promising a sprint to 100km/h in just 4.1sec.

As there’s no wagon available in BMW’s equivalent M3/M4 range, we’ve opted to put the new Audi up against thunderous stalwart of the performance wagon category, the mighty Mercedes-AMG C 63 S to see which of these middleweights is the new family favourite.

This pair are natural competitors, the two Euros representing the best of their respective brands’ performance pillars.

While on the face of it, the two wagons offer similar levels of carrying capacity, comfort and features, it’s what’s under their skin that delivers each its unique personality.

The Mercedes-AMG C 63 S Estate retains its thumping 4.0-litre twin-turbo V8 with seven-speed automatic transmission driving through the rear wheels, while the Audi favours its legendary quattro all-wheel drive system paired with its new powerplant and eight-speed shifter.

The Merc wins the numbers game, with power rated at 375kW and a thumping 700Nm besting the Audi’s 331kW and 600Nm. But that doesn’t translate to a straight line win, as each promise an acceleration time to 100km/h of 4.1sec.
Each car is similarly priced too, in standard spec, they’ll set you back just under $160,000 (plus on-road costs).

These vehicles are suited to a broad range of buyers as they meet the needs for space and load-carrying capacity but also hit the mark for sports performance. They’re also likely to appeal to drivers who haven’t yet made the switch to SUV-life and still want a car that handles with no compromises.

Drivers looking for a suite of assistance technologies will also likely gravitate towards these models which feature lengthy features lists including adaptive cruise control, lane keeping assist, blind spot monitoring and rear cross-traffic alert.

Each is a true five-seater proposition, with practical features like two ISOFIX rear child-seat mounts, heaps of legroom and more than decent boot space for a family load of gear. The Audi is now longer and wider than the Mercedes-AMG and that translates to a shade more boot space (505 litres against the C 63 S’s 490).

Both cars have a folding second row to accommodate Ikea-sized loads or outdoorsy-gear such as mountain bikes with ease and the Audi has a lower boot floor for easy access for pooch.

In base specification, it’s the Audi RS 4 Avant that comes out cheaper, starting from $152,900 while the Mercedes-AMG C 63 S Estate weighs in at $159,340 (both prices plus on-road costs). Our test vehicles added a few extras too…

Adding optional 19-inch alloy wheels to the C 63 S brought its total to $160,330 while Audi added a bunch more content: Optional extras on the RS 4 included red pearl effect paint, 20-inch alloy wheels, Technik package including head-up display, gloss black styling and RS design plus carbon inlays, pushing its as-tested price to $165,546.

The Audi additions all added to the appeal of the RS 4, the exterior design highlights giving the Avant a more aggressive stance while the interior finishes, including Alcantara steering wheel, red-edged seat belts and RS details added extra finesse to the cabin.

While Audi’s clever virtual cockpit infotainment system is standard on the RS 4, head-up display is only available as an option, where it is included as standard in the C 63 S. The Audi also offered wireless phone charging (via the Technik pack) and the now ubiquitous Apple CarPlay and Android Auto compatibility.

At this price point, of course each vehicle attracts luxury car tax.

For servicing, Audi expects to see you every 12 months or 15,000kms while Mercedes-AMG stretches its service intervals to 20,000kms. RS models are not eligible for Audi’s three-year service plan, however, Mercedes-AMG does offer capped-price servicing for the C 63 S. Expect to pay $3380 over the first three years if you choose to service with a Merc dealer.

Both Audi and Mercedes include three years’ roadside assistance.

Fuel economy figures came surprisingly close to their claims… when driving with a feather foot. Audi claims an ADR Combined figure of 8.9L/100km while the Mercedes’ larger engine promises 8.7L/100km. In practice an easy freeway cruise 8.4 in the RS 4 and 9.5 in the C 63. Sink the boot in, however, and those numbers quickly average-out at 11.4 and 12.0 respectively.

There’s no mistaking the walloping presence of the Mercedes-AMG C 63 S Estate. It looks mean, sounds mean and the torque from its monster V8 delivers a knockout blow to driver and passengers even at mid-strength acceleration.

Its rear-drive configuration appeals to the driver in us. Shift the car into Sports+ mode, which enhances both throttle response and tightens up the suspension, and there’s just the right about of squirrelling from the rear to make the drive exhilarating. Here’s a car that makes you know that you’re alive!

Noise matters as much as performance in this category and on this front the Mercedes delivers too. Its sports exhaust elicits a playful growl, which when paired with the uber-dynamic Sports+ mode, urges you onwards to find the twisty stuff as soon as possible.

Not to be outdone, the Audi RS 4 Avant is just as engaging on road. While the sports exhaust doesn’t have the same brash note as the C 63 S Estate, it does still make the prerequisite pops and crackles under shifting so the drive is just as satisfying, if slightly less exhausting [ba-da-ching].

The cabin is refined and more sophisticated and the seating is more comfortable in the RS 4. Front seats offer better lateral support for smaller passengers than the C 63 S, which, when both cars are driven back-to-back feels a shade more brutish than the accessible Audi.

Drive-wise the Audi wagon is just as much fun as the Mercedes monster. While it lacks the aural sensation, and the slippery rear, it produces a drive which is balanced, confident and assured. Audi’s quattro all-wheel drive system and excellent Pirelli tyres grip the road well, handling changes in the road camber with aplomb and permitting the driver to punch the car out of corners without any resultant fidgeting.

Both of these vehicles are exceptional all-round performers so it is a challenge to pick out too many negatives. As we’ve experienced in every Mercedes-AMG C 63 S body-style, the sports suspension on the wagon is stiff which compromises its ride quality on rough roads, and even in comfort mode can be a bit bouncy for passengers.

When it comes to the Audi, its technology integration is more up-to-the-minute than the older Mercedes-AMG system so it is disappointing that a sportscar must-have like head-up display isn’t included as standard fitment. The Technik package which bundles head-up display with LED headlights and Audi phone box including wireless charging seems pricey at $3900 on top of an already expensive vehicle.

We also can’t understand why Audi doesn’t offer capped-price servicing on its RS models – How much servicing does a vehicle really need in its first 45,000kms..?

Last time I drove the Mercedes-AMG C 63 Estate in a comparison it was against the Holden Commodore SS V-Series Redline Sportwagon of all cars. Why? Because we wanted to see if a locally-tuned sub-$60,000 car could shake it against a real Euro beast.

Then, the Holden won thanks to its value and ride quality.

This time, the three years later, the older Merc was up against a pricier contender and it loses again, but only just.

Toe to toe with the Audi RS 4 Avant, the battle was close-fought, and to be honest, my fellow tester Feann Torr and I would have been more than happy to take either car home.

The Mercedes-AMG C 63 S Estate does have more grunt and it’s a fantastic car to pilot. But the Audi feels just as quick, and it is just as showy even if it isn’t quite as raucous.

Assess the vehicles for refinement and long-term appeal and the RS 4 Avant wins out on both measures. The Mercedes-AMG C 63 S Estate offers good levels of luxury and finish but had significant wind noise experienced at both A-pillars and developed a creak from the instrument binnacle.

In contrast, the Audi’s cabin felt quieter and more refined and therefore a better proposition for a longer term relationship. Add this to its up-to-the-minute styling and a more balanced ride and it is the RS 4 Avant that takes the win. Just.

How much does a 2018 Audi RS 4 Avant cost?
Price: $152,900 (plus on-road costs)
Engine: 2.9-litre six-cylinder twin-turbo-petrol
Output: 331kW/600Nm
Transmission: Eight-speed automatic
Fuel: 8.9L/100km (ADR Combined); 11.4L/100km (as tested)
CO2: 202g/km (ADR Combined)
Safety Rating: N/A

How much does a 2018 Mercedes-AMG C 63 S Estate cost?
Price: $159,340 (plus on-road costs)
Engine: 4.0-litre eight-cylinder twin-turbo-petrol
Output: 375kW/700Nm
Transmission: Seven-speed automatic
Fuel: 8.7L/100km (ADR Combined); 12.0L/100km (as tested)
CO2: 202g/km (ADR Combined)
Safety Rating: N/A