IT is not difficult to work out why the A6 is Europe’s bestselling car in its class.

Stylistically the understated Audi avoids the divisive styling of the BMW 5 Series, conservative air of the E-class, and the Lexus GS’ aggressive stance.

Inside, the A6 is even further ahead, thanks to class-leading space, its extremely high-quality design, build and presentation and overall refinement.

But, GS aside, the Audi trails its rivals in the sales stakes in Australia, revealing that we are either not as sophisticated as our continental counterparts by preferring the other German vehicles, or – and this might be closer to the truth – the A6 has never been that much of an inspiring drive.

Frankly, even in the competent 3.0-litre TDI quattro configuration, the Audi has been let down in the areas of ride absorbency and steering feel, compared to the other cars. It seemed that – until now – the A6 felt too hard underneath, yet did not deliver the expected weighty steering feel that keener drivers might demand as the normally inevitable upshot.

Making matters worse is the fact that the ‘5’, ‘E’ and GS are all rewarding sports sedans in their own way. Clearly, the A6 was out of its depth in this company.

So expectations were not high when, after almost five years on the market, Audi has blessed its beautiful but flawed mid-sized luxury sedan with a subtle facelift, to accompany a rather larger heart-transplant operation.

Frustratingly, on the Australian launch in February 2009, the media was unable to sample the volume-selling 3.0 TDI V6 diesel, popular 2.0 TFSI petrol, potential cat-among-the-pigeons base 2.0 TDI diesel base model due in May 2009, or vastly underrated Allroad quattro 3.0-litre TDI.

Instead, Audi could only roll out three relatively fringe-dwelling petrol-powered A6 models – the $92,000 2.8-litre FSI quattro, $112,500 3.0-litre TFSI with the first supercharged V6 engine that the company has ever offered, and the ballistic RS6 sedan that costs almost $270,000.

First off then, the 2.8-litre FSI quattro: visually and inside, the A6 keeps the pressure on its peers with superb detailing, to make it a front-runner in the dealer showroom desirability stakes. This car looks and feels every bit the sumptuous luxury car it aspires to be.

Indeed, it also rides with somewhat better ability than before on the rural roads we sampled the cars upon – although some surfaces did reveal annoying levels of tyre noise intrusion.

We also have no complaint about the sweet revving, silent-running 2.8-litre naturally aspirated V6. Paired to Audi’s slick Tiptronic automatic, this powerplant imbues this A6 with a strong, silent and salubrious demeanour.

However, the vast sweeping bends, mixed with the at-times oddly cambered tight corners, revealed that the A6 is still no driver’s car.

Yes, it grips gamely, tips into turns with immediate response and little fuss, and keeps all occupants well padded from all the irregularities going on with the road underneath, but the Audi does not glide through an apex with the taut body control or unflappable feel of its rivals. The fact is that the steering is still too bereft of feel for drivers to feel absolutely confident at speed in this vehicle.

The truth is, however, that these roads probably don’t do the A6 justice. A Mazda MX-5 or Audi R8 driver would have relished the drive route that – in the A6 – simply showed it off as a large, heavy sedan with a disheartening dislike for snaking blacktop.

On the other hand, we believe that on the highway, and particularly in inclement weather or slippery conditions, the A6 in quattro AWD guise would shine head and shoulders above the others, and demonstrate a real difference in how stable and secure it feels.

Funnily enough, a winding mountain pass did put the unbelievably capable RS6 sedan into perspective.

Backed up by its Dynamic Ride Control adjustable shockers, quattro AWD, sports-orientated stability control, honed suspension and weightier steering responses in Sport mode, this car belies its size and (it must be said) A6 parenting to be one of those devices that distorts time and travel distances.

Drop the driver’s window to savour that sublime V10 exhaust bellowing as the engine thunders on its upper rev range, and the RS6 is a titan on wheels, delivering progress in giant strides while making the lucky person behind the wheel feel quite invincible.

Again, the electrifying tactility of – say – an Audi RS4 or BMW M5 is absent, but the RS6 is still supernaturally talented as an incredibly powerful ground covering missile of a motor car. Away from a racetrack or on an autobahn, there is little to differentiate between the Audi and its rivals – until, of course, the conditions go askew and this car’s AWD comes to the fore.

The RS6 is too expensive, though. Audi says that at least 30 per cent of this car’s price is made up of taxes …

Finally, we drove the A6 3.0-litre TFSI quattro – the only truly all-new engined variant on the launch day.

Somehow, it felt a little better in the body control department than the 2.8 FSI quattro we blasted around in a little earlier in the day. But it is still no driver’s car in steering feel and feedback.

Yet this new powerplant is sensational, with a substantial yet linear delivery of power from low revs, and without the coarseness that is normally associated with supercharged units. In fact, we struggled to hear or feel the Roots blower.

We relaxed the pace a little after a while of driving the 3.0-litre TFSI quattro enthusiastically, and realised that – in the final analysis – Audi has achieved many of its goals with the revised A6.

On the strength of all three cars driven, the ride seems more compliant than before. The engines are certainly at least as good as corresponding rivals’ efforts, while the overall dynamics will feel first class to the majority of non-demanding owners who just love light and fuss-free steering, and sufficiently responsive for keener drivers to live with. But we know that there are better drives out there.

Still, as the A6 is still extremely strong in so many other areas, we can see this car holding its ground in Europe anyway – at least until the new-generation E-class and 5 Series relegate it to ageing also-ran status.

Until that time, the Audi deserves to sell better in Australia.