The exterior was changed only slightly from the "C4" Audi 100 – new front and rear lights, new radiator grille, similarly with chassis and engine and transmission choices.

From its launch in late 1994, the Audi S6 was powered by a 2,226 cubic centimetres (135.8 cu in) turbocharged inline five-cylinder petrol engine (parts code prefix: 034, identification code: AAN) with a Bosch Motronic electronic engine control unit (ECU), producing a motive power output of 169 kW (230 PS; 227 bhp) at 5,900 rpm and 326 N⋅m (240 lbf⋅ft) at around 1,950 rpm, on high octane "Super Plus" 98RON unleaded petrol.

The vehicle was available with a standard six-speed manual transmission (five-speed only in North America), and Audi's dynamic Torsen T-1 Quattro permanent four-wheel-drive system.

The S6 Plus, developed by Audi's wholly owned high-performance subsidiary, quattro GmbH, was available for sale during the 1997 model year only (production from June 1996 to October 1997).

In 2002, the A6 received a facelift, with revised headlight and grille design, exposed exhaust tips, and slight changes to accessory body moldings, and tail light colour from red to amber in North American models.

The 1.9-litre Turbocharged Direct Injection (TDI) was tweaked to produce a maximum power output of 96 kW (131 PS; 129 bhp), and 310 N⋅m (229 lbf⋅ft) of torque, and was mated to a six-speed manual gearbox.

Compared to the regular A6, the allroad featured an advanced air suspension system, allowing for increased ground clearance; larger diameter all-terrain tyres, and flared fenders and bumpers with matte finish, giving it a distinct appearance and more overall flexibility over varying terrain.

The standard adjustable air suspension system can lift the car high enough to provide 208 mm (8 in) of ground clearance; a low-range mode (an option with manual transmission), absent from other Quattro-equipped vehicles, can be selected with the touch of a button.

When used together, the two systems made it possible for the allroad to complete an official Land Rover test-course, thus far it is the only car-based SUV that has been proven capable of doing so in testing.

The 'Ur-' is used in the German language, as a prefix to signify 'ancient' or 'early ancestor' (e.g., great-grandmother is Urgroßmutter), and is used informally by car enthusiasts worldwide to refer to the original[16] Audi Quattro that was produced from 1980 to 1991 (the "Ur-Quattro").

This has the advantage of minimising the wealth of buttons normally found on a dashboard by replacing them with controls that operate multiple devices using the integrated display.

Full LED headlamps with Automatic high beam switching or Audi adaptive light (Xenon) with variable headlight range control.

[45] The refresh includes styling tweaks to the car's exterior, engine line-up, transmission and MMI infotainment system with faster Tegra 3 processor, Handwriting recognition, Audi connect Telematics with 4G mobile internet (and online updates for the navigation map), and advanced Matrix LED headlights.

The entry-level Audi A6 2.0 TFSI FrontTrak (front-wheel drive) with a 2.0-litre turbocharged inline-four, received a seven-speed dual-clutch automatic that replaced the previous Multitronic CVT (continuously variable transmission).

[citation needed] Most obvious, the allroad received special bumpers and fender flares, giving it an aggressive offroad appearance.

The allroad comes standard with an adjustable air suspension system can lift the car high enough to provide 208 mm (8 in) of ground clearance; a low-range mode (an option with manual transmission), absent from other quattro-equipped vehicles, can be selected with the touch of a button.

When used together, the two systems made it possible for the allroad to complete an official Land Rover test-course, thus far it is the only car-based SUV that has been proven capable of doing so in testing.

[50][51] The A6 L (built in China for the Chinese market as a long wheelbase alternative to the standard A6) was unveiled in 2012 in Guangzhou International Sports Arena.

[52][53] Available as the S6 saloon and S6 Avant, they included twin-turbo V8 engine rated 420 PS (309 kW; 414 hp) at 5500–6400 rpm and 550 N⋅m (406 lbf⋅ft) at 1450–5250 rpm, recuperation and start-stop systems, cylinder deactivation, Active Noise Cancellation system, seven-speed S tronic transmission, quattro permanent all-wheel drive system with a self-locking center differential and torque vectoring (optional sport differential), adaptive air suspension lowers the body by 10 mm (0.4 in), internally ventilated brake discs (optional carbon fiber-ceramic discs), matte black calipers with S6 logos, 8.5Jx19-inch cast aluminum wheels in a unique five parallel-spoke design (optional seven different 19- or 20-inch wheels (four from quattro GmbH), including 20-inch titanium-look wheels with a five-arm rotor design), 255/40-series tires, Audi drive select driving dynamics system, optional dynamic steering, single-frame grille with aluminum applications and chromed horizontal double bars, exterior mirrors feature aluminum-look housings, S6 sedan with spoiler on the trunk (S6 Avant has a roof spoiler), diffuser on the rear bumper in platinum gray with an aluminum-look offset edge, four elliptical chrome-tipped tailpipes, choice of eight body colors (including exclusive shades Estoril Blue, crystal effect and Prism Silver, crystal effect), body decorated with S6 and V8T badges, leather sport steering wheel with colored stitching, footrest and pedals and soft keys of the MMI operating system in an aluminum-look finish, decorative inlays in matt brushed aluminum (optional carbon, fine grain ash natural brown, layered Beaufort oak), choice of 3 colours for headlining, instrument panel, carpet and seats (black, lunar silver and goa beige (only for the seat upholstery)); Pearl Nappa leather and Alcantara seat upholstery (optional Milano and Valcona leather), height-adjustable sport seats with power lumbar supports and embossed S logos (optional power-adjustable comfort seats with memory function, power-adjustable S sport seats with integrated head restraints).

Electric power is supplied via a 14.1 kWh lithium-ion battery, with all-electric range of 80 km (49.71 mi) for constant 60 km/h (37.28 mph) drive.

[58] Available in Saloon and Avant bodies, they are versions of A6 S line with 177 PS 2.0-litre TDI or higher engines (excluding S6) in front-wheel-drive or Quattro all-wheel-drive configurations, for the UK market.

[59][60] It is a version of S6 Avant with increased engine power to 560 PS (412 kW; 552 hp) at 5700–6700 rpm and 700 N⋅m (516.3 lbf⋅ft) at 1750–5500 rpm, cylinder on demand system deactivates intake and exhaust valves of 4 cylinders (2, 3, 5 and 8), eight-speed tiptronic transmission with shortened shift times and D and S driving modes, quattro permanent all-wheel drive system with torque vectoring with self-locking center differential with an elevated locking value and oil cooler, adaptive air suspension lowering body by 20 mm (1 in) (optional tauter sport suspension plus with Dynamic Ride Control), option is dynamic steering, four internally vented 390 mm (15 in) diameter brake discs in wave design with a wave-like outer contour (optional 420 mm (17 in) diameter carbon fiber-ceramic brake discs with anthracite gray calipers), black six-piston brake calipers (optional red brake calipers), electronic stabilization control with Sport and off modes, high-gloss 20-inch forged wheels in a seven twin-spoke design (optional 21-inch cast wheels in high-gloss silver, polished black or polished titanium-look), matte aluminum applications on the body, high-gloss black protective grille at the front of the car, the bumpers, the fender, sill flares and the large roof spoiler; rear diffuser with two large elliptical exhaust tailpipes, a choice of 9 body colours (including exclusive shade Daytona Gray matte), dial instruments feature black faces and white dials and red needles, flat-bottomed three-spoke multifunction steering wheel, illuminated entry sills, driver information system (DIS) sport RS logos, RS6-specific driver information system, footrest and pedals and switches in the MMI navigation plus terminal in aluminum finish, decorative bezel surrounding the retractable monitor in a piano finish, interior door openers in a delicate double-bar design, standard Carbon inlays (with six additional materials as options), standard black headlining (optional Silver or black Alcantara), RS sport seats with side bolsters and integrated head restraints and RS6 logos upholstered in black Alcantara and leather with diamond quilting at center sections (optional honeycomb-quilted Valcona leather in either black or Moon Silver), optional power-adjustable deluxe seats with memory function, two sportily molded rear seats (optional three-person bench seat), xenon plus headlights, LED rear lights, a tire-pressure control system, illuminated entry sills, custom driver-information system, parking system plus, cruise control, three-zone automatic air conditioning, MMI navigation plus with MMI touch and the 10-speaker Audi sound system.

As part of the Audi A6 Avant launch in the UK, BBH London, Knucklehead, The Whitehouse, The Mill produced the 'Hummingbird' TV commercial, directed by Daniel Barber.

Johann Strauss's 'Open Road, Open Sky' was sung by legendary American baritone and automobile lover John Charles Thomas.

In addition, 60 second and 30 versions of the ads were supported by press, print and radio campaigns, as well as a presence on the Daily Telegraph's iPad app.

3.0 TDI model includes 7 kW (9.5 PS; 9.4 hp) electric powered compressor, Euro 6d temp emission standard compliance.

[89] 20 years allroad includes a choice of three body colours (gavial green, glacier white, Soho brown), 19-inch wheels in exclusive design, black sport seats with leather/Alcantara upholstery, aluminum inlays and illuminated door sill trims.

[90] It is a version of A6 Avant with 40 mm (1.6 in) wider body on each side with flared wheel arches, front headlights from Audi A7, optional RS-specific Matrix LED laser headlight with darkened trims with dynamic turn signal, 4.0 TFSI engine rated 600 PS (441 kW; 592 hp) at 6250 rpm and 800 N⋅m (590 lb⋅ft) at 2050-4500 rpm with a separate lithium-ion battery.

[99] Audi A6 allroad quattro won Auto Bild Allrad's All-Wheel Drive Car of the Year under the Crossover category.

Michael Wines of The New York Times wrote that "More than a perk, the black Audi is a rolling advertisement for its occupant’s importance and impunity in a nation obsessed with status.