Under the changes, the A6 saloon and Avant models gain styling revisions, including an updated singleframe grille, the air inlets, the bumpers, the side sills, the rear lights and the tailpipe. There’s also the addition of xenon headlamps as standard for SE models, and LED headlights with dynamic “sweeping” rear indicators for S line versions and above.

Matrix LED headlights, incorporating clusters of LED bulbs which can be individually dimmed when sensors detect oncoming or following traffic to automatically divert their beams around obstacles, is added to the list of options for all A6 and S6 variants and standard for the RS 6 Avant. 

Inside, there’s new upholstery and headlining colour choice for S line versions, as well as new versions of the top-of-the-line MMI navigation plus and Audi connect elements. The MMI navigation plus system now uses a more powerful Tegra 30 graphics processor from Audi's partner Nvidia, and includes MMI touch, which enables the driver to scroll and zoom in lists and maps via a touchpad. Audi connect now brings tailored internet-based services and new media streaming apps to the car via the latest LTE high‑speed data transmission standard for ultra-fast 4G click-through and download functionality.

The Audi phone box option is also now available – this enables occupants to connect their mobile phones to the car‘s antenna for improved reception simply by placing them in the phone box compartment.

Audi has also augmented the range of driver assistance systems, topped by adaptive cruise control with stop & go function. The range includes Audi side assist, which uses radar to check behind the car when changing lanes, works closely together with Audi active lane assist, which prevents unintended lane changes. The night vision assistant now includes more functions.

The latest A6 also offers improved power and efficiency for the engine line-up. The new range for the A6 and A6 Avant comprises four TDI engines with either four or six cylinders and either single or twin turbo charging, offering a reduction of up to 22% in CO2 emissions.

As before, the line-up includes the 2.0 TDI “ultra” unit, which offers the highest efficiency, with up to 64mpg and CO2 of as little as 114g/km A6 Ultra (click here for road test).

There’s also changes to the trio of 3.0-litre six-cylinder TDI units, with a single-turbo V6 with 215bhp, which replaces the existing 201bhp version, and is followed by a 268 variant, also with a single charger, which takes over from the outgoing 242 unit. At the top of the range, power for the 3.0 TDI clean diesel biturbo is upped to by 7bhp to 316bhp.

The high‑performance diesel is paired with an eight‑speed tiptronic automatic transmission. All other engine variants are linked to either a newly designed six‑speed manual gearbox or a seven‑speed S tronic twin-clutch transmission. Front-wheel drive versions gain a fully redeveloped dual-clutch transmission replaces the familiar eight-speed multitronic continuously variable transmission.

Sports suspension lowered by 20mm is standard for the A6 S line and optional for the SE model, while the former can also be equipped with S line sports suspension which lowers the body by a further 10mm. Both models can also be fitted with electronically controlled adaptive air suspension.

Meanwhile the range continues to be topped by the S6 and S6 Avant using the 444bhp 4.0-litre TFSI petrol engine, and the RS 6 Avant with a 552bhp 4.0-litre TFSI engine.

The new A6 and S6 Saloon and Avant ranges are expected to open for order in the UK during September, with first customer deliveries in late 2014.

On-the-road prices are to be confirmed but expected to start from £32,000.