“Sample the potent
  3.0-litre turbodiesel in
  Audi’s desirable new
  A6 and you may never
  want petrol again...”

THEY SAY THAT if you want to get ahead, the one thing you need is a first-class nose. No, really. We're not kidding. And the one thing you can't help but notice about Audi's striking new A6 is that it's blessed with a highly-distinctive nose. Audi calls it a 'trapezoidal single-frame radiator grille'. One glance and the fabulous Grand Prix cars from the Thirties immediately spring to mind, along with legendary motor racing names such as Nuvolari and Auto Union.

Framed with an unbroken trapezoidal 'ring' of chrome flanked either side by wide headlamp units above even wider low-slung air intakes, the A6's aggressively bold grille styling instantly grabs your attention even from some distance away. But it's only when you approach the car that you realise that the new A6 is much larger than the model it replaces. With an additional 3.26 inches added to the wheelbase, 1.77 inches of extra width and a 4.72 inch increase in overall length, the A6 is the widest and longest saloon in its class.

Thanks to some well-judged styling, the A6 exudes the air of refined elegance that has become synonymous with the four interlinked rings of the Audi badge. Study the coupé-style roofline and uncluttered muscular flanks, underscored by an elegant rising swage line that runs the length of the car along the base of the doors.

Along with a bigger bodyshell, Audi has also introduced a better choice of engines — including their latest direct injection petrol engines and potent yet economical turbodiesels. Kicking off the range is a 2.4-litre V6 petrol unit, followed by another V6, the 256bhp 3.2 FSI, and a 335bhp 4.2-litre V8. Three turbodiesels are available: a 2.0 four-cylinder and two V6s — a 2.7 and the potent 225bhp 3.0-litre. It doesn't take Nostradamus to predict that — given their excellent refinement, accessible performance and better fuel consumption — it will be the turbodiesels that sell in the greatest numbers.

Audi expects at least half of new A6 buyers to go for the 225bhp 3.0 TDI quattro SE, which comes with Audi's outstanding Tiptronic automatic transmission fitted as standard — a good enough reason for us to test it.

Audi has developed this engine to the stage where it has none of the conventional diesel drawbacks. Just all the plus points. This new 3.0-litre diesel engine is currently the most advanced oil-burning powerplant you can buy. But, as undoubtedly interesting and important as it is, you don't need to understand about the piezo fuel-injection technology or the variable geometry turbocharger with twin intercoolers. All you need to know are the numbers: a hefty 225bhp and even more torque than the range-topping 335bhp 4.2 V8 petrol engine. And such is the nature of the turbodiesel beast that the TDi is more sparing with the fuel.

The new, bigger, A6 has two aces up its sleeve that will leave buyers feeling extra smug about their choice of car. First and foremost is the distinctive body and the increased internal dimensions, resulting in a classy and comfortable cabin with masses of space.

Settle in the superb sport-style front seats or lounge luxuriously in the rear where — along with a large, well-padded armrest — you'll find a generous helping of head, shoulder hip and leg room. Both front chairs have comprehensive electric adjustment, including excellent lumbar support and adjustable under-thigh support. Each also enjoys six-stage heating that reaches parts that other heated seats never do.

Tucked away neatly in the two-tiered glovebox is a 6-CD autochanger, plus a handy slide-out drawer is fitted under the passenger's seat. The new A6 is indeed one of best-built and most accommodating executive saloons around, easily on a par with limousines costing far more. Four adults would be perfectly comfortable, thank you, motoring from London to Gstaad or Prague. In fact, wherever it takes your fancy.

There's plenty to feast your eyes on and it's easy to see just what makes Audi cabins so appealing. Note the beautiful build quality and the first class materials — wood inlays, supple leather and soft-touch plastics — used throughout. And the attention to detail. For example, the elegant, crafted and polished satin aluminium inner door handles, and convenient one-touch up/down electric windows fitted not just in the front but in the rear as well.

Clarity, functionality and usability are the three watchwords for the handsomely finished dash that angles the instruments and the upper section of the centre console towards the driver. The dash extends across the fascia to include the 7-inch multi-media interface colour screen at the top of the centre console. Instrumentation is straightforward. Two attractive teardrop-shaped displays, one containing the large speedometer and the other the rev-counter, are sited dead ahead of the driver.

Both are easily seen through the upper crescent of the three-spoke multi-function steering wheel, which is trimmed in leather with especially comfortable perforated leather being used on the 'most gripped' sections. Smaller analogue gauges, for coolant temperature and fuel, are also easily monitored. Positioned between the major dials is a clear driver's display for a range of information from the currently engaged gear and audio status to the outside temperature and additional navigation information. And, just in case you forget what the new corporate Audi grille looks like, the centre airbag cap in the steering wheel is shaped to mirror its design.

Instrument graphics are sharp white, with red needles and easy on the eyes. Happily, all controls and switches have a precise, engineered feel to them. Drivers will find the ignition key slot has moved from the steering column to the dash and not only is this more convenient, but it's also a welcome safety feature — rarely seen, but one that should quickly make its way into other cars. Also thoughtfully-sited is the 'talk' button on the steering wheel, for voice control of MMI functions including telephone, audio and repeating navigation prompts.

The latest A6 gains a version of Audi's Multi-Media Interface system first seen on the A8. Located — along with the push/pull button for the electro-mechanical parking brake — on the central transmission tunnel behind the gearshift, it is within easy reach of the driver. MMI controls various functions through a dashboard screen and operates via a foolproof rotary switch and menu buttons. Intuitive to use it controls, among other things, the climate control, stereo and navigation and it really is one of the most easy-to-use systems of its kind.

Generously laden with desirable equipment as standard, the 3.0 TDi comes with MMI, dual-zone climate control, a first-rate 10-speaker sound system with CD player, automatic headlights and wipers, cruise control, six airbags, a driver's information system, electric front and rear windows, heat-insulating tinted glass, servo-assisted boot lid locking, electrically operated and heated door mirrors with power fold-back, auto-dim rear-view mirror, electro-mechanical parking brake and stylish alloys wheels. There's also a full complement of high-tech braking, anti-skid and traction control systems.

Another valuable benefit of the A6's bigger bodyshell is the vast, 546-litre boot which is big enough to sleep in! And thanks to the hassle-free split-fold rear seats there's even greater flexibility for long loads. There's also additional storage space in the well for the full-size spare wheel beneath the boot floor.

The second ace up the A6's sleeve is the compact all-new state-of-the-art V6 3.0-litre diesel engine installed in the engine bay. One of the world's lightest diesel engines, it is unbelieveably smooth and responsive and delivers massive mid-range punch over a wide rev range. Its 331lb ft of torque is available from a low, near-idling speed of 1,400rpm all the way up to 3,250rpm, yet it remains remarkably hushed well past UK motorway speeds limits — a key factor in the A6's overall refinement. Actually, it's only when you're really 'going for the burn' that you can tell what's under the aluminium bonnet. Under normal acceleration and when cruising — 90mph requires a near-silent 2,500rpm in top — you'd be hard-pressed to guess. It really is as good as that.

The official combined fuel consumption figure of 33.2mpg makes more sense when you consider the performance figures: 0-62mph acceleration of just 7.3 seconds combined with a maximum speed of 150mph. Apart from the speedometer, there's little to warn you that you've crossed into three-figure speeds. But exercise some self-restraint and wringing more miles out of each gallon should be easy enough.

Whatever your chosen driving style, the 80-litre fuel tank will ensure that stops for fuel are as far apart as possible. To save you checking your calculator, that could be close to 700 miles at the official 43.4mpg touring figure. Our best figure was 37.4, but then we weren't on an economy run. Over 575 miles of hard testing on varied roads and under mixed conditions, we recorded an average 33mpg — almost exactly matching the combined official 33.2mpg figure and strongly beating the official 23.5 urban figure.

The new, sixth-generation A6's body is not only larger than that of the previous model, but it is 34 per cent torsionally stiffer too. Making good use of the rigid new chassis is a fully independent set-up with four-link front suspension and self-tracking trapezoidal-link rear suspension adopted from the Audi A8. And it takes but a short time behind the wheel to appreciate the improved driving characteristics of this latest executive saloon from Audi.

Some spirited driving quickly shows the 3.0-litre to be a sporty totty at heart. Balanced and level through sweeping bends and corners, it is equally composed and capable when asked to perform sharp direction changes. Select the autobox's Sport mode and push as hard as you like and you'll find grip levels are reassuringly high, backed up by the quattro permanent 4WD drivetrain. Most of the time, however, it's so unobtrusively good that you never give it a second thought, taking the confidence-inspiring stability for granted. Only when the weather turns bad do you consciously appreciate just how secure the A6's handling is.

Our car was equipped with the optional Sports suspension package that, for £300, provides a 20mm lower ride height with stiffened damper and spring rates and additional front and rear anti-roll bars. Despite a low speed ride that can verge on the firm side (read firm, not hard), the overriding impression is one of a superbly refined long-distance cruiser — one endowed with a well-considered mix of compliant ride comfort and a handling-biased agility that's capable of indulging and rewarding the driver whatever his or her driving mood.

The speed-sensitive rack-and-pinion power steering works well. Fingertip-light for effortless parking and easy city driving, it firms up noticeably as road speed increases to provide positive straight-ahead accuracy and stability at high speed when it tracks straight and true. A good turning circle combined with a usefully quick turn-in makes the A6 easy to place on the road.

Fitted with ABS, electronic brake-force distribution and brake-assist, the ventilated all-disc brakes feel full-blooded, the pedal reacts instantly and generates immediate stopping power. They're also easy to modulate and make reassuringly quick and tidy stops every time.

What you will be aware of, and truly appreciate, is the suave Tiptronic transmission. Using the wheel-mounted paddle shifts or the conventional selector lever you can manually flick through the ratios, dropping — should you want to — more than a single gear at a time. Driven in manual mode the Tiptronic, if left, will shift up just before maximum engine speed is reached.

The autobox's Dynamic Shift Programme means you'll always find yourself in the right gear at the right time — another sensible reason, along with up and down changes so silky as to be almost undetectable, as to why most of the time you'll be content to let the Tiptronic 'box go about its business in its own imperturbable way. Enhancing the near-indomitable sense of refinement to be enjoyed while travelling in this new A6 is the impressive absence of noise from the engine, the wind or even the meaty 225/50 17-inch Continental Sport Contact tyres.

Your safety is well looked after, underpinned by a stronger crash structure than the previous model. In addition to the self-evident active safety benefits of quattro permanent four-wheel drive, the A6 is equipped with stability and traction control, anti-lock brakes, six airbags (including dual-stage front, side and head) as well as active head restraints to minimise whiplash.

Our test car had the optional active headlamp system: Xenon-plus headlights that swivel with the front wheels, allowing the driver to, literally, 'see around corners'. And it works: you really can. Other optional high-tech safety kit includes DVD Sat-Nav, voice activation for the Multi-Media Interface system, run-flat tyres, electronic tyre pressure monitoring, radar-assisted cruise control and adaptive air suspension.

Audi has hit gold with this new 3.0-litre TDi A6. It looks good, feels good and by golly it is good to drive. It's difficult to fault. And once you've had your turn behind the wheel, you'd be hard-pressed — particularly if you're in the market for a prestige executive saloon — not to want one on your driveway.

Audi A6 3.0 TDi quattro SE Tiptronic | £31,150 Maximum speed: 150mph | 0-62mph: 7.3 seconds Overall test MPG: 33mpg | Power: 225bhp | Torque: 331lb ft Visit Audi's website