Engine, 0-60mph and gearbox
The cheapest engine is a 201bhp 2.0-litre diesel (badged 40 TDI), which has enough grunt to haul a fully loaded car with ease. However, the 50 TDI diesel has a 3.0-litre V6 engine and generates even more shove from relatively low revs. With 282bhp, it's effortlessly quick on the move, so is worth considering if you have deeper pockets.
We haven't tried the 242bhp 2.0-litre petrol engine (45 TFSI), but the range-topping 335bhp 3.0-litre petrol is seriously rapid. It can do 0-62mph in just 5.3 seconds, and strong acceleration is on tap from really low revs. It's a fantastic engine.
The A6's automatic gearboxes can leave you momentarily hanging when you’re looking to pull away swiftly from stationary, but they shift suitably quickly on the move.
Suspension and ride comfort
Go for entry-level Sport trim and you'll get regular suspension, while S line and Black Edition models have a lower and stiffer sports setup. You can also have more sophisticated air suspension although this is available exclusively on range-topping Vorsprung models.
Both of the non-air setups deliver a supple enough ride over large bumps, such as sleeping policemen, but tend to thump over sharper-edged scars and potholes. The stiffer sports suspension tends to jostle you around a bit more at motorway speeds, but the difference isn't dramatic.
Those who regularly travel with the boot heavily loaded might be wise to consider Vorsprung trim for the air suspension it brings. This has a self-levelling function to prevent heavy loads from causing the car to sag on its rear wheels, and it's also the best version of the A6 when it comes to dealing with bumpy roads.
While the A6 Avant doesn’t scythe through bends with the precision of a Jaguar XF Sportbrake, it mostly handles predictably and securely.
We say 'mostly', because how the cheapest 40 TDI model sends all of its power to the front wheels is given away by a tendency for its steering wheel to tug unnaturally in your hands under hard acceleration. However, Audi’s traction-enhancing quattro four-wheel drive system is optional and solves this issue; it's standard on all other engines in the range.
But while the A6 is certainly capable through the bends, its steering doesn't stream a great deal of feedback to your fingertips. If you want a more rewarding estate, consider the XF Sportbrake or the smaller BMW 3 Series Touring.
Noise and vibration
The engines are mostly smooth and quiet, with the 55 TFSI petrol deserving special mention for its creamy power delivery and supremely hushed character.
That said, the diesel engines in the A6 aren't quite as refined as those in the BMW 5 Series Touring, and there's also a bit more road noise on the motorway. Compared with most similarly prices rivals, such as the XF Sportbrake, though, the A6 Avant impresses in this area.