Road-hugging rocket

By Ghaith Madadha - Oct 13,2014 - Last updated at Oct 13,2014

The go-to company for fast estate cars, Audi’s RS cars have included the now classic 1994-95 RS2 and several RS4 and RS6 models. Termed an “Avant” in Audi-speak, the innovative Ingolstadt car maker’s first ever wagon was offered in a performance version.

Built on the then-advanced C3 platform, the 1983-91 Audi 200 Quattro Avant transplanted the legendary rally-proven Quattro sports coupe’s turbocharged five-cylinder engine and four-wheel-drive onto a premium executive-class estate, and as such was ground zero for the explosively powerful RS6 Avant.

A car for practically any occasion, the RS6 Avant combines executive car refinement, estate car versatility, devastating performance, tenacious road-holding and a slew of high tech safety, infotainment and efficiency features.

Sharper, edgier and more nuanced than its predecessor, the current RS6 Avant’s tight chiselled lines and well-integrated design lend it a thoroughly robust and sculpted “hewn-from-granite” sense of power and presence. With inward-squinting and heavily browed headlights, huge inward-angled lower air intakes and upright gills, vast trapezoidal grille and new tarmac-scraping air-splitter, the RS6 Avant has a hungry and predatory feel to it.

A consistently level waistline is a refreshing change from competitors’ fashionably rising waistlines, which with wide haunches and enormous 285/30R21 tyres on split five-spoke black alloy wheels, lend a reassuringly road-hugging aesthetic quality. A gently arcing roofline ends with an abrupt tailgate spoiler, while the rear end features sporty dual exhausts and air diffuser.

Thoroughly engineered

Built on an aluminium-intensive platform with aluminium bonnet, boot, doors and front wings, the current RS6 is 90kg lighter than its predecessor. Underneath, the RS6 uses a traditional Audi Quattro four-wheel-drive layout with an in-line engine positioned low and closely ahead of the front axle, for a low centre of gravity and superb front wheel traction and resilience to torque-steer.

Incorporated in the gearbox, Audi’s traditional and innovative hollow shaft Quattro four-wheel drive is a light, compact, efficient and tension-free system. With a 60 per cent rear-bias for a more sporting feel, the RS6 Avant’s Quattro system can variably reapportion up to 85 per cent power rearwards or 70 per cent to the front, while an electronically controlled rear differential allocates power right and left as required.

With a smaller and lighter four-litre twin-turbo V8 engine slung in-front, the current RS6 may lose 20BHP to its 572BHP five-litre twin-turbo Lamborghini-derived V10 predecessor, but the lower front weight pays off in terms of handling, while the new engine is also more efficient and develops 37lb/ft more torque. Combined with a lighter weight, the current RS6 in fact delivers improved performance, including 0.7-second quicker 0-100km/h acceleration.

A direct fuel injection design with stop/start system and subtle four-cylinder deactivation when cruising on motorways or driving in traffic also translates into 9.8L/100km combined cycle fuel efficiency and 229g/km carbon dioxide emissions, which for a two tonne four-wheel drive estate with supercar performance are nothing short of frugal.

Supercar swift

With its two twin-scroll turbochargers mounted between its V8 cylinder banks, the RS6 short induction pipes greatly reduce turbo spool-up time and translate to excellent low end responsiveness and an almost total absence of turbo lag. Developing a mighty 552BHP throughout 5,700-6,700rpm and a gut-wrenching 516lb/ft torque over a rich 1,750-5,500rpm band, the RS6 Avant’s four-wheel drive ensures that none of this is wasted on wheel spin, and with vice-like traction ferociously bolts off the line.

Devastatingly swift, the RS6’s completes the 0-100km/h dash in supercar-like 3.9-seconds. The RS6 tops 305km/h when de-restricted as part of a dynamic package plus, which also features powerful fade-resistant ceramic brakes and hydraulically linked front damper dynamic ride control suspension providing firmer body control.

Responsive low-down, abundant in mid-range and explosively powerful at its top end, the RS6 Avant’s mighty twin turbo V8 delivers effortlessly swift and muscular acceleration and flexibility as it surges through a broad sweet spot of escalating power underpinned generous torque, and is mated to a smooth but quick-shifting eight-speed automatic gearbox with manual paddle actuated sequential shifts.

Through the RS6’s drive select menu, one chooses from pre-set vehicle mode combinations, or tailors such settings to one’s preference. These include throttle and gearbox responsiveness, a more vocal exhaust note, firmer steering feel, stiffer adaptive air suspension setting and more aggressively sporty differential setting. With the hard-edged “dynamic” modes selected across the board, the RS6 becomes a more ferociously focused beast.

Tenacious traction and road holding

Renowned for its high-speed stability, the RS6 Avant’s highway refinement, reassuring confidence is matched by little else on the road. While a planted high speed experience absent of fidgeting or dynamic awkwardness was expected, the RS6 Avant’s alert and responsive handling wasn’t. Given its legendary Quattro driveline, the RS6 was expected to deliver the sort of tenacious traction and heroically high levels of grip that it does.

However, the surprise was that despite a hefty 2,010kg kerb weight and nose-heavy layout with engine lying outside of the wheelbase, the RS6 Avant felt agile and light on its feet, with sudden direction changes executed in a crisp and tidy manner without the distinctly nose-heavy feel of the early Quattro and in-line front-drive Audis.

Eager into corners, the RS6 Avant’s front end digs in faithfully and ensures a tidy cornering line, while its taut air suspension works hard to effectively control weight transfers through both fast sweepers and through sudden switchbacks.

Through a corner, the Quattro system and centre and rear differentials ensure power is distributed between front and rear, and right and left to be best utilised, which translates to class-leading road-holding for both safety in low traction conditions and phenomenally quick and confident handling as it goes through corners like it was riding on rails. With cabin refinement high, and levels and grip from its low profile tyres, the RS6 does however ride on the firm side, especially in its dynamic suspension mode.

Classy and cavernous

Tightly planted at speed, taut through corners and buttoned down on vertical rebound, the RS6 is firm, smooth and sophisticated, while its level riding air suspension’s comfort mode takes the edge off the large alloy wheels and stiff ride, and delivers decent comfort. A plush and ergonomic cabin with high quality fit, finish and design, the RS6 has a serious ambiance to it.

Comfortable, well adjustable and supportive, the RS6’s sports seats are superb and feature lumbar support and an optional massaging function. With clear instrumentation, classy minimalist layouts and materials, adjustable thick flat-bottom steering wheel, user-friendly controls and infotainment screen, the RS6 offers a terrific driving position and good road visibility owing to a big glasshouse.

Well-spaced in the rear, the RS6 Avant also features a cavernous load capacity of between a minimum 565- to a maximum 1,680 litres. Well-kitted, the RS6 features innumerable mod cons and safety features from Isofix child seat latches, automatic tailgate, Bluetooth music streaming and many others, but unfortunately only an iPhone jack and no USB connectivity.

Optional packages are similarly extensive and include things like four-zone climate control, heated seats, HUD display, 360° camera and several semi-autonomous driving aids including active lane assistance, adaptive cruise control with “Stop & Go”, and parking and night vision assists. Materials include standard carbon inlays and Alcantara and leather upholstery, and include optional brushed aluminium and more luxurious leather among other trim options.

TECHNICAL SPECIFICATIONS

Engine: 4 litre, twin turbo, in line V8 cylinders

Bore x stroke: 84.5 x 89mm

Compression ratio: 10.1:1

Valve train: 32 valve, DOHC, direct injection

Gearbox: 8-speed automatic, four-wheel drive, limited-slip rear differential

Power distribution, F/R: 40 per cent/60 per cent

Power, BHP (PS) [kW]: 552 (560) [412] @ 5,700-6,700 rpm

Specific power: 138.2BHP/litre

Power-to-weight: 274.6BHP/tonne

Torque, lb/ft (Nm): 516 (700) @ 1,750-5,500 rpm

Specific torque: 175.3Nm/litre