Audi RS6 Avant 2009 Review

If somebody had an inkling to search for roads that replicate the Audi RS6's home turf - Germany's wide- open stretches of unlimited autobahn where power and speed rule absolutely - they'd be well advised to avoid the west coast of Tasmania. Nothing about the roads down here is predictable apart, perhaps, from their ability to throw out traps for the overconfident and incautious. Speed advisory signs at the entry to turns are often conspicuous by their absence, and the bitumen in corners is often warped and distorted by logging trucks, carpeted with dead furry beasts and strewn with gravel on their inner edges. And you can never quite guess on which side of the road Farmer Giles will be approaching in the opposite direction. Just the place to unleash a 426 kilowatt, two tonne-plus monster of velocity, then.

And yet, of course, if you had to pick anywhere in Australia to go for a drive, this would be it. That's why the Targa Tasmania features a number of stages on these very roads every year; although pace notes and zero oncoming traffic must help raise confidence levels. Part of Tasmania's charm is its lack of crowds (less than half a million people live on an island twice the size of Belgium), and even then, anywhere west of Hobart has the population density of an AFL final at a Sydney stadium. And twice as much entertainment.

Apart from the scenery - ranging from the Englishness of towns like New Norfolk and Ouse, to the mossy alpine meadows near Cradle Mountain - the diversion comes from the sheer audacity of the car itself. Audi has already availed itself to Lamborghini's V10 to produce the S6 and S8 sedans; now the bar has been raised in an effort to trump the BMW M5 and Mercedes-Benz E63 AMG. To achieve this, Audi borrowed and re-tuned the 5.2-litre V10 from Lamborghini's Gallardo - you can do that when you're the boss - and shoe-horned it into the A6's engine bay. This wasn't especially difficult, as the engine is quite compact, and the platform calls for a longitudinal donk.

But Audi's engineers didn't stop there. They added a turbocharger to feed each bank of cylinders, ran them at a maximum of 23psi boost pressure, and suddenly had outputs of 426kW and 650Nm. And, like previous Audis carrying the RS nomenclature, this one's a wagon. A booted version is on the way, arriving early next year just in case there's still some potential buyer worried about being mistaken for Clark or Ellen Griswold. Or Aunt Edna, for that matter.

Delve a little deeper under the RS6 Avant's engine lid and there's evidence this is far more than a straight powertrain swap. Apart from the turbo plumbing and different internals for a reduced compression ratio - still high at 10.5:1 - the V10's capacity has been down-sized to 5.0 litres compared with the Lambo's 5.2, because forced induction looks after any concerns about torque delivery. Grunt is just as important as power, with the peak of 650Nm arriving as low as 1500rpm, and there's no end of technology that has gone into its delivery, including direct fuel injection and valve timing that is continuously variable on inlet and exhaust over 42 degrees of crankshaft angle. Lubrication is via a dry sump to alleviate packaging and surge concerns.

Transmission is via a conventional six-speed auto driving all four wheels, while the mechanicals are clothed in a relatively subdued body measuring a substantial 4.93 metres. It's worth noting that despite the V10's stumpy 670mm length (including ancillaries) every gram of its 278kg mass hangs over the front axle line. That might be balanced by the Avant's extra glass areas and longer roof panel at the rear, but all-up weight is 2025kg, not including me.

In terms of acceleration, that mass is tempered (or more accurately, overwhelmed) by an engine output equating to one kilowatt for every 4.8 kilograms, so performance figures verge on the extraordinary. Audi claims the RS6 will hit 100km/h from standstill in 4.6 seconds, and we were just a tenth off that pace during later testing at Oran Park. The big wagon storms the standing 400 metres in 12.7 seconds, recording a 186km/h terminal speed. With the auto in drive, the RS6 brushes aside the 80-120km/h overtaking test in a scant 2.7 seconds.

Figures are one thing, and as I drive past the Tarraleah hydroelectric power station on the Lyell Highway between Hobart and Queenstown, I note that its output of 90 megawatts is only 211 times that of the RS6, even if its carbon outputs are a lot less. Anyway, I'm more interested in what this engine (sorry, car) can do and, unsurprisingly, it can warp time.

Squeeze the throttle and whatever seemed to be minutes down the road suddenly arrives within a heartbeat. Part of the spatial and temporal dislocation comes from how quiet the car is - engine noise is limited to a distant rumble most of the time with an odd burp of deeper bass on upchanges, and wind noise is almost non-existent - but mainly because acceleration is always available, always massive. The breadth and elasticity of the power delivery, from just above idle to 6500rpm, means instant surge.

As an aside, this is one of the few cars in which I found myself constantly using the wheel-mounted gearshift paddles instead of letting the auto look after changes itself. In the RS6, it's wise to do your own downshifts because if the gearbox kicks down a cog or two by its own devices, the instant torque jump is enough to catapult you out of a corner on the wrong side of the road, or into the back of a logging truck.

Which could be quite expensive given the RS6 Avant is a $271,000 proposition, or around $30,000 more than an M5 sedan or an E63 Estate. To be fair, it has more power than either and lacks little in terms of kit, even if adaptive cruise and carbon-ceramic brakes are options.

Still, it's difficult to equate the RS6 with luxury when you experience the ride quality on the more appalling of Tasmanian road surfaces. Three damper settings are offered, and it's a struggle to work out which is least comfortable. So-called 'comfort' works well enough on moderately paced, open roads with good absorption of road shock, but allows far too much body float and unwanted movement for hard cornering. The median setting - 'dynamic' - ties things down much better for greater handling precision, but the ride quality becomes uncomfortably firm, while 'sport' delivers such bone-shattering harshness your teeth will splinter. Hit a hump in the road, and the damping rebound is enough to suck your lunch out of your ears.

This would be understandable if the RS6 was one of the world's best handling cars, but it falls short of that. Granted, entry speeds are likely to be high given there is an infinite ability to accelerate from one corner to the next. That's no criticism of the brakes - 390mm six-piston jobbies at the front - which stop well and barely fade, just one of driver judgement.

But all that weight forward of the front axle inevitably means a lack of enthusiasm to turn in, a fair degree of understeer once it does, and then on softer suspension settings the rear end wobbles and breaks loose sideways, especially if a quick direction change is needed. More than once I thanked the ESP for saving the day, and even enjoyed the frustrated growl of the V10 as it was throttled back by the stability control's brain.

As I said, tight and lumpy roads aren't the best place for an RS6, because on open and flowing tarmac it is poised and relaxing; an irresistible force. There's other stuff that's not perfect about the car: operating the MMI (Audi i-Drive) at speed isn't easy, and the Euro-spec stereo is hopeless at picking up AM radio.

But for sheer spine-bending thrills, the ability to eat distance, the solid dependability of the car and day-to-day useability of the body style, it's hard not to find the RS6 awesome. Give me a smooth road, and I might even love it.

Images: Cristian Brunelli