IF you have an established, respected and authentically premium brand, the customers will find you.

That's the view of Audi at least, a car maker which believes itself to be the most progressive premium brand on the market.

The figures certainly uphold those claims. The company has invested heavily in expanding its range, now offering more than 40 model types.

In September, for instance, the marque sold more than 22,000 cars in the UK, which is 20 per cent up on last year.

An avalanche of new models to hit the streets shows no sign of slowing down, with 15 arriving this year alone.

Whatever your view of Audi, and for many it comes simply down to taste or habit when choosing between the big three German brands and executive offerings from the likes of Jaguar, Lexus or Volvo, you can't deny the company's range is beautifully engineered.

None more so than the A6 saloon, a car which courtesy of a slightly longer wheelbase and more width than its predecessor, offers a huge amount of leg and shoulder room.

And because almost a quarter of its surface area, including doors, bonnet, bumpers and boot lid, are made of aluminium it is extremely light, so more efficient as well.

A choice of four TDI diesel engines and a pair of petrol units paired with a variety of transmissions and in SE and S line spec is up for grabs with prices from £30,810.

Most popular is the single 2.0-litre diesel in the line-up, a 177PS engine which allied to six-speed manual transmission can return an average 57.7mpg while emitting just 129g/km of CO2.

A mixed test route taking in both motorway and country roads revealed the more powerful 3.0-litre V6 quattro version, boasting 245PS of punch and Audi's S tronic twin clutch transmission, to be a car of outstanding ability.

It is capable of almost 48 miles per gallon, for the light-footed driver at least,  and boasts enough punch to hurtle the saloon to 62mph in a fraction over six seconds.

In top spec S line it costs £10,000 more than the entry level A6 but is kitted to the hilt with goodies like xenon headlights with daytime running lamps, sports suspension, larger alloy wheels, upgraded leather upholstery and added S line trim finishes.

That said there's so much techno wizardry on offer from Audi these days that you can easily hike up the tab by another ten grand from the options list.

That's with extras like comfort seats with heating, cooling and massaging functions, acoustic glazing, a head-up display, a 15-speaker 1,200-watt audio system, TV reception and online services including news and weather info.

Dressed up to impress or clad in base grade SE comfort, the A6 is a joy to drive with a magic carpet ride for four adults guaranteed.

Its only letdown is the uncomfortably perched position a centre rear passenger has to occupy, straddling the car's wide transmission tunnel.

At the performance end of the range is the fiery S6 featuring a new twin-turbo V8 TFSI petrol engine that also powers the S8 and S7 Sportback models.

Quilted leather seats, carbon fibre inserts in the dash and centre console hint at the 420PS of punch beneath the bonnet - enough to blast the S6 from 0-62 in 4.7 seconds and on to a Governed 155mph.

Yet despite the power on tap, this variant is capable of an official average of 29.4mpg, possible in no small part due to the S6's cylinder deactivation system that disengages four of the eight cylinders under part load to maximise efficiency.

The S6 is also a model which perfectly demonstrates the breadth of extras available from the Audi options bin.

For instance the tab of a car costing from £54,310 can be considerably hiked up with the likes of ceramic brakes at £8,650, 20-inch titanium-look alloys at £1,625, Night Vision assistant with pedestrian detection at £1,510, dynamic steering at £1,210 and Bang & Olufsen advanced sound at £6,300.