In truth, it would be hard to make an argument for a petrol model over this superbly competent oil-burner, so hushed is the diesel clatter, and such is the reserve of torque at low to mid revs. This diesel may well be quieter than its unleaded brothers, especially as the 3.2 petrol finds the need to drop a gear to gain momentum.
This powertrain's best trait is the progressive delivery. You no longer need to adopt the traditional turbodiesel all-or-nothing attitude towards throttle control and can enjoy a direct relationship between your right foot and rate of forward motion. And its worst? Fuel consumption; even the official figures suggest a best of 40.3mpg. We found gentle motorway driving delivered a more realistic 36.7mpg – okay if you're used to petrol but a little disappointing for a diesel.
Since its first attempt at air suspension, on the previous Allroad, Audi has had plenty of opportunity to refine the system, and air-filled struts can be found on regular A6s and A8s. On the new Allroad the air suspension gets five operational modes. The first three settings – dynamic, automatic and comfort – mirror those of the standard A6 system, adjusting ride height with road speed.
The fourth 'Allroad' mode similarly links height with speed but with a greater inclination to jack up the suspension – to the extent that at town speeds the car rises perceptibly higher than standard saloons and estates. Finally, lift mode (operable below 22mph) gives ground clearance of 185mm, 23mm less than the previous model – further indication of the Allroad's positioning clear of the Q7 and its 240mm.
On road, the system works best in either comfort or automatic mode, smoothly sorting out any road undulations with the best low-speed ride compliance of any A6 yet. Given the general softness of the suspension, energetic driving results in reasonable body roll, yet ultimately the Allroad hangs on securely before eventually understeering.