Audi A6 review

The 2.0-litre diesel Audi A6 (the 40 TDI) is a tad slow off the mark, but only because its standard seven-speed dual-clutch automatic gearbox hesitates when you put your foot down. That's also why its 0-60mph time (8.1sec) is slower than with the BMW 520d and Mercedes E220d. Once you're rolling and the gearbox has woken up, though, the A6 is plenty brisk enough and will outperform its rivals in a 30-70mph sprint.

If you want more poke, there’s the 3.0-litre V6 50 TDI diesel or the 55 TFSI petrol. They’ll manage 0-62mph in 5.4sec and 5.1sec respectively, with the 50 TDI offering a bit more low-down urgency. That’s handy as the eight-speed automatic gearbox fitted to the diesel is a little hesitant to change down on the move and get moving from a standstill.

Both non-adaptive set-ups deliver a supple ride over large bumps, but even the softer non-S line springs tend to thump over sharper-edged potholes. That's not particularly irksome in itself, but the suspension springs back up after a bump, which quickly becomes tiring. The adaptive suspension with coil springs is the best fit for the A6. They’re still on the firm side, but deliver a far more sophisticated balance between control and compliance, and deal with broken asphalt effectively while controlling body movements over dips and crests extremely well.

So, should you go the whole hog and get a V6 Vorsprung with the range-topping air suspension? Well, no. In most circumstances, the air set-up is softer and more compliant than the standard adaptive suspension, but if you strike a large, sharp-edged obstacle with any pace, it produces a forceful thump that is out of place in such a sophisticated luxury car.

You might notice a few engine vibrations through the pedals and steering wheel of the diesels, but the A6 keeps road and wind noise to a minimum. The suspension noise is more noticeable than in immediate rivals, though, at least in cars fitted with standard springs and dampers.

The seven-speed dual-clutch automatic gearbox you get with the 2.0-litre diesel and 3.0-litre petrol can be slightly jerky when parking or in stop-start traffic. The 3.0-litre diesel has a more conventional eight-speed auto which is better at slow speeds but less refined when you accelerate hard (it hesitates then suddenly flares the revs with a substantial jolt). By contrast, the plug-in hybrid generally shifts smoothly, and switches between petrol and electric power almost imperceptibly.