The most basic engine is a 2.0-litre diesel, but even that gives a decent turn of pace. As you step up the engine range, you’re struck not just by the stronger performance, but also by how effortless that performance becomes. The flagship 3.0-litre bi-turbo TDI barely needs revving to keep up with traffic – but when you do, it’s astonishingly quick. The one petrol engine is also a 3.0-litre, but it needs working harder than the diesels.
The A6 Avant feels planted and secure on the motorway. What’s more, it grips well through bends and remains calm and assured unless you lift off suddenly mid-corner. SE models generally ride well, albeit with a slightly firm edge at low speeds, but S line cars have lowered sports suspension that gives a noticeably firmer, less comfortable ride.
This is not an area in which the A6 Avant excels. Not only do its door mirrors generate some wind noise at motorway speeds, but there’s too much road noise over coarse surfaces. At least the 2.0-litre diesel engine is refined, aside from a bit of vibration that you feel through the clutch pedal. The larger engines are smoother still, partly thanks to their extra cylinders.
The vast majority of A6 Avants are sold as 2.0 TDIs, and with CO2 emissions of just 129g/km and an average of 57.6mpg, it’s not hard to see why. The other diesels are also impressively clean and efficient, and resale values should be good, making most models a sensible purchase. The exception is the petrol, which is expensive to buy and run.
The A6 more than lives up to Audi’s reputation for excellent cabin quality. The materials, build and attention to detail are faultless throughout and the overall ambience isn’t far off that of Audi’s pricier A8 luxury saloon. The A6 didn’t score particularly highly for reliability in our latest JD Power survey, but it didn't disgrace itself, either.
Like the A6 saloon, the Avant is brimming with the latest safety kit, including six airbags and stability control. Optional extras include rear side airbags and a system that steers you back on course if you start to wander from your lane on the motorway. The A6 saloon earned the maximum five stars in Euro NCAP crash tests, and the Avant should be just as safe.
The A6 has supportive seats and there’s plenty of adjustment to help the driver get comfortable. The upper dashboard is refreshingly clutter-free, too. However, the MMI system – which links a rotary control knob and onscreen menus – takes a bit of getting used to because the four function buttons grouped around the dial relate to different commands depending on which menu you’re in at the time.
The boot is well shaped and there are lots of practical touches, including straps, lashing points and an optional hands-free opening system that raises the tailgate when you wave a foot beneath the rear bumper. While carrying capacity is slightly up on the 5 Series Touring, though, it’s still well behind the E-Class Estate’s, whether the rear seats are up or down. The cabin is harder to fault because there’s generous head- and legroom for four.
Every A6 comes well kitted. SE trim includes satellite-navigation, leather upholstery, dual-zone climate control, automatic headlights and wipers, and front and rear parking sensors. There’s a hefty premium for S line trim, which adds extras such as lowered and stiffened suspension, larger alloys, sports seats, bespoke front and rear bumpers, xenon headlights and LED rear lights.