Flat out in the Outback

The time had come. Through the windscreen the Stuart Highway was headed straight for the horizon, eventually vapourising into a liquid mirage.

Apart from the HSV GTS lolloping along behind, I was alone, driving an Audi RS 7 Sportback on the only public highway in Australia where there is no speed limit.

The RS 7’s 4.0-litre twin turbo V8 engine was purring sleepily at just over 100km/h. Time to get that 412kW and 700Nm working.

Foot to the floor and for a milli-second there is no reaction as engine, torque converter eight-speed auto and the all-wheel drive system’s centre diff mesh. Then, with serious intent, the RS 7 accelerates, its fat, flatulent exhaust note quickly drowned out by rising wind noise and tyre roar.

Numbers starting with 1 are despatched within seconds and the big digital speedo starts cycling through the 2s like a slot machine. At 240km/h there seems to be the slightest pause, but maybe it’s just me cracking the throttle slightly on the coarse surface. But then on we charge, right up to 292km/h indicated.

There, the cut is soft but definite. The top speed is astonishing, but less so than the rate at which the RS 7 was still gathering pace when it hit the limiter. I let it bump and nuzzle against the limiter for a second or two, just to make sure, then start heading down the slope, back to what now feels like a glacial 150km/h or so.

Not that long ago there were no speed limits on much of the NT’s open-road network. But that changed in 2006 when a 130km/h limit was introduced. Now, a 220km stretch of the Stuart Highway has, since February, been derestricted. It’s a trial run by the NT government, a commitment it made when in opposition before the last election.

The point of the Stuart Highway derestriction is not so everyone can take powerful cars outback and drive flat-out. It’s more about recognising this is a place where distances are massive and getting to your destination before dusk is a great idea considering the amount of wildlife that hops, crawls, trots and gallops onto the road at night.

The ‘speed kills’ lobby has roundly berated the decision, but the NT government points out there hasn’t been a speed-related fatality on this section of road in years.

In our two days on the Stuart Highway researching, videoing and noting for this story we rarely saw any vehicles going really fast. Sure, there were quite a few pushing up to and over the old 130km/h limit, but the majority of traffic — the convoys of grey nomads towing double bogey caravans behind 4x4s, the one-tonne utilities, the locals in various battered Falcons and Commodores, the motorcycles and the three-wheelers — mostly hung closer to 100 than 130km/h. The speed-restricted trucks and road trains had no choice.

And that’s an important point about this road. If you think it’s continually empty and quiet then think again. This is the highway that connects Alice Springs with Darwin far to the north. Go south and eventually at Port Augusta in South Australia you will hit Highway One and the road to Adelaide... or Perth. So traffic is constant. We would not have gone more than five minutes without seeing another vehicle.

Then there is the road itself. It is classic, old school, Aussie highway. One lane each way, with narrow, rough edges and only a couple of metres of dirt run-off before you are into the bush. Yep, lush, green vegetation that often stands a metre or more high. It’s not constant, but there is a surprising amount of it thriving on recent rains. Presumably, there is also plenty of wildlife hidden in there too.

The highway’s surface is predominantly coarse chip and is rougher than it looks. While there aren’t heaps of potholes, there are plenty of waves and undulations that feel quite sharp rolling under the fat rubber and adjustable sports suspensions of these two cars. Those low-profile tyres also quite enthusiastically tram track on the channelled surface.

So if you want to make a high speed run then you have to pick your moment. The good news is that so much of the Stuart runs so far, flat and straight, the visibility so good, the opportunity will present itself before too long.

Which brings us back to 292km/h. While a memorable moment and proof of the RS 7’s incredible powertrain, at that sort of speed you become very conscious of how rapidly everything is happening and of the car’s reaction to every change in texture in the road. Button down to 150-160km/h and it’s all far more manageable. In fact, it feels like we are dawdling across this vast landscape.

It’s still a pace that means slower traffic is regularly popping over the horizon and retreating towards us. So there were plentiful opportunities to revel in the brutal acceleration of both cars. We’ve broken out the times recorded on the VBOX (see break-out below), bearing in mind these were real world ‘just tromp the throttle and go’ numbers. We didn’t even bother with the Audi’s launch control. No surprise the results were a few tenths slower than the claims. But hey 4.4 seconds to hit 100km/h is still pretty cool, and 13.0 to 200km/h is darned impressive (especially from the driver’s seat!).

It was fascinating to jump back and forth between these two cars. There is no doubt the RS 7 is the more refined product with a superior interior quality and incredible solidity. But then at $238,500 (plus on-road costs and options) versus $95,490 (plus ORCs) it no doubt needs to be.

Mind you, what would an HSV be without that lumpy V8 idle, an obvious thump from the six-speed auto on kickdown as you hammer the throttle and a combination of induction and exhaust that bellows, shrieks and takes obvious and massive lungfulls of air as the car charges forward.

Even so, the supercharged LSA 6.2-litre V8 simply cannot match the sheer surge of the RS 7. The Audi gradually pulls out an advantage that becomes more pronounced as speeds rise. At least in part that must be due to an aerodynamic advantage; the GTS looks good in that bluff Aussie four-door way, the Sportback is squashed wide, flat and low by comparison.

As the Audi whips like a low-flying spaceship through a series of bends at close to 200km/h, the perspective gives more context to the high speed than simply watching a shrinking red dot.

The RS 7 doesn’t have it all its own way though. The GTS tops out at 264km/h indicated (262.3km/h actual), which is actually higher than the standard 250km/h limit for the RS 7. But our test car was fitted with the $4900 Dynamic package, which lifts the top speed to 280km/h.

Pay another $25,840 (yes the comma is in the right place) and you get the Dynamic package plus, which lifts the governed top speed to 305km/h and adds yet more gear including ceramic brakes (sensible!).

It’s also noticeable that in the real world claimed fuel economy (which we’ve included in the performance table below) isn’t the one sided battle that is presented in the specs, where the HSV claims 15.7L/100km and the RS 7 and extraordinary 9.8L/100km. The Audi has idle stop-start, but that’s not much help out on the Stuart.

The HSV’s rear-wheel drive gives it a lighter, lither feel and the tuning of its electric-assist power steering is more delicate and connected. Under hard acceleration as the nose lifts, the Audi’s optional dynamic variable steering system goes quite wooden.

The GTS’ third-generation MRC (Magnetic Ride Control) semi-active suspension also feels more adept on Australian roads in its less aggressive Tour and Sport modes. It is still liveable in Track for that matter (it stays in Sport when the Driver Preference Dial is toggled to Performance). However, at ultra-high speed it feels a bit like a stone skipping across water.

The RS 7’s RS adaptive air suspension really needs to be in its Comfort setting for it not to be too jolting. Dynamic is just too stiff for the conditions we found on the Stuart. This is an autobahn tune for sure.

While HSV’s DPD system and Audi’s Drive Select can both dial preferences for a number of vehicle performance functions, the RS 7 driver can delve deeper into everything from engine response through gearchange to damping individually and can also store those preferences permanently.

Whatever settings you end dialling up we can assure you these are both great cars with tremendous performance. The beauty of the Stuart Highway north of Alice is you can actually go and give them a run to their full potential without fear for your license.

But, remember, be sensible about it.

It was an unintentional and momentary breach, but as all Victorians know, that doesn’t cut it with the Traffic Camera Office.

So on one hand, we have the Stuart Highway north of Alice Springs; it is single lane each way, quite rough, quite narrow and is by no means empty. On this 220km stretch there is no speed limit.

On the other hand, there is the Peninsula Link tollway. Brand new, sparsely travelled, excellent surface, brilliant sight lines. It has a 100km/h speed limit.

Out on the Stuart Highway it is beholden on the driver to behave in a safe manner. On Peninsula Link – and every other open road in Victoria – we are reduced to automatons, relying on cruise control to save our bank accounts – and our ticket.

The contrast between nanny State and self-reliant Territory is obvious.