AUDI’s A6 Avant with attitude, the Allroad quattro, continues to shock and awe with its impressive balance of on and off-road abilities.

Which is a little more than we might initially have expected from such a cheapskate attitude towards entering the soft-road SUV fray.

The competition (Mercedes M-class, for example) at least offered purpose-built occasional off-roaders, complete with their vertically oriented, family wagon-meets-bus-meets-truck looks.

And now, with the addition of a 4.2-litre V8 version to supplement the rapid twin-turbo 2.7-litre V6 and the vigorous and economical turbo-diesel, the blatantly passenger car-sourced Audi Allroad strengthens its case even further.

Sheer torque is something the Allroad has never lacked and the V8 has it in bucketloads. Unassisted by forced induction – as are the petrol and diesel V6s - the V8 Allroad winds out no less than 380Nm of torque at just 2700rpm.

Couple this with a 220kW output at 6200rpm and you have an engine able to take the Allroad’s 1.8-tonne bulk in its stride.

The petrol and diesel turbos might rate among the better examples of how a forced induction engine should respond to throttle commands, but there is never any getting away from the sheer, instant brute force of a decent, high-tech V8.

In fact, at times there is a hint of the superlative RS6 supercar within the Allroad V8, much of it to do with the dual exhaust system that emits a noticeable, throbbing sound, and the fact that both engines share a 4.2-litre capacity.

But the engine is not the same as used in the V8 A6 sedans. It’s the new, cropped version, now also seen in the S4 sedan, which measures 52mm shorter through relocation of the camshaft drives from the front to the back of the engine (and the use of maintenance-free chains instead of toothed belts) and weighs around 5kg less through more extensive use of magnesium.

The more compact engine was needed because the Allroad’s frontal structure is different (read shorter) to that of regular A6s.

The result is a very fast, very responsive, very satisfying Allroad. The five-speed sequential auto - the only transmission available with the V8 – is a bit abrupt at times and often delays a downshift from fifth so long that when it does come, there is an unexpected rush of power.

Used forcefully, it enables easy matching of speed on freeway feeder lanes as well as rapid passing on the highway. There is a penalty in terms of fuel consumption though, exacerbated by the smallish 70-litre tank which limits comfortable cruising range to less than 500km.

The V8 Allroad is the premium version of a vehicle that already rates pretty highly in terms of road presence, bumping the price well past the $100,000 mark but justifying it with an almost fully ticked standard equipment list.

This includes dual, automatic air-conditioning, leather trim, power front seats (without a memory setting on the driver’s side), five-speed Tiptronic transmission, Xenon headlights and alloy wheels – but does exclude things like satellite navigation, power sunroof and parking sensors. For the money, you might expect at least one of those.

But that the Allroad V8 is a luxurious way of going slightly off-road there is little doubt.

The suspension and driveline systems work together to give the Audi better all-round ability than you might expect – justifying the Allroad nameplate.

The all-independent suspension, for one, uses air springs that enable it to do various things.

For instance, it can be set to increase ground clearance so the Allroad can more comfortably travel rutted, bumpy tracks. The system is always busily at work, maintaining a level stance regardless of load – although the fact it will automatically select minimum ride height (25mm less than the regular setting) at speeds above 130km/h is largely irrelevant in Australia.

In all, it is capable of operating at any of four different height settings, from 142mm up to the full 208mm.

In practice the suspension feels tighter (less absorbent of bumps) than a regular A6, while the higher-riding natural stance means it tends to heel over more noticeably on bends, while exhibiting unmistakable understeer.

This latter is a common characteristic among all-wheel drives and is electronically counteracted, past a certain point, by the standard stability control system. The Allroad never feels as nimble as a regular A6 though.

The full-time 4WD driveline incorporates traction control, electronic differential lock and a self-locking Torsen centre differential. The Audi is able to maintain forward progress if only one wheel has traction.

The V8’s more than 1.8-tonne mass is comfortably dealt with by the fully ventilated, all-disc system that includes ABS and electronic brake-force distribution in its repertoire. But pedal feel is a little spongy.

The mid-size interior, which offers quite generous leg-space in both front and back, is pretty useful when it comes to loading up, although it lacks the vertical aspect of regular SUV load areas.

There’s the usual split-fold rear seat, in this case able to fold flat in one single, fluid movement – although the whole assembly feels very heavy. It incorporates a cargo blind/intrusion barrier that can be used whatever the chosen rear-seat configuration.

The fact that this all-wheel drive Audi has a greedy, space-taking rear differential also means that a temporary spare is used.

Our test car suffered from a few unexpected squeaks and rattles which were less indicative of any lack of structural strength than the fact it had already experienced a harsh life as part of the fleet that introduced the V8 version to the national motoring press.

The Allroad remains the most car-like of the top-level SUVs, yet is a proven performer off the beaten track with abilities that might surprise some sceptics.

The only disadvantage here – apart from the fact you wouldn’t really want all that leather and soft-pile carpet caked up with gobs of wet mud – is that neither the V8 nor the turbo-diesel offer the manual transmission option available in the petrol V6, along with the dual range that allows low-speed creeping over tough obstacles.

The fact remains that the Allroad buyer can decide whether to be tough and rugged only on the road, or in the bush also.

The V8 Allroad might not be a Porsche Cayenne Turbo or an ML55 AMG Benz, but it still has the punch to challenge many a high-performance sedan.