The Typ 4F A6 was released in 2004. Designed by Satoshi Wada in 2001, this model was visually an evolution of the C5, but was lengthened to 4,927 millimetres (194.0 in), and incorporates the new Audi trademark "single-frame grille". Like other contemporary Audis, the A6 had a "tornado line" that ran just below the sheetmetal's shoulders and joins the front and rear light clusters.

The C6 iteration of the A6 features more sophisticated technology. Most notable is the Multi Media Interface (MMI), which is a system controlling in-car entertainment, satellite navigation, climate control, car settings such as suspension configuration and optional electronic accessories through a central screen interface. This has the advantage of minimising the wealth of buttons normally found on a dashboard by replacing them with controls which operate multiple devices using the integrated display.

On the internal combustion engines, the new Fuel Stratified Injection (FSI) direct injection technology was introduced. Although the line of engines represents the same progression as the former model, all engines were new. The multitronic continuously variable transmission continues as an alternative for front-wheel drive models, alongside a new six-speed tiptronic automatic transmission available in the four-wheel drive models. Audi's "trademark" Torsen-based quattro permanent four-wheel drive is available in most of the lineup, and standard in the most powerful models. quattro is not available on the multitronic variants of the A6, but is available on the manual and tiptronic gear systems. Conversely the tiptronic system is not available on the front-wheel drive variants of the car. The six-speed manual gearbox is available with the 3.2-litre V6 engine, but not for the North American market.

The Avant arrived during the course of 2005. The A6 allroad quattro made its debut in 2006, and as before, is an off-road ready version of the Avant, available with either a 2.7-litre V6 or 3.0-litre V6Turbocharged Direct Injection diesel engines, or a 3.2-litre V6 or 4.2-litre V8 petrol engine.

C6 facelift

Audi unveiled a facelifted "C6" Audi A6 on 12 August 2008, at the Moscow International Motor Show. The refresh incorporates some modern Audi design cues to keep the A6 current with the rest of the Audi lineup.