The entry-level diesel is a 198bhp 2.0-litre four cylinder, badged 40 TDI. It’s the slowest of all the engines but will still have you cruising at – or beyond – motorway speeds with relative ease. It's the only engine available without quattro four-wheel drive fitted as standard, and the front-wheel drive version officially cracks 0-62mph in 8.3sec, but if you option the quattro system this drops to 7.0sec.
To get a diesel with more serious poke you need one of the two 3.0-litre V6 engines. We haven’t tried the 228bhp 45 TDI yet, but the 282bhp 50 TDI is quick. It’s grunty from low revs and has plenty left in the mid-range to propel you along rapidly without it breaking a sweat. In fact, it'll all but match anything a BMW 630d will do in terms of acceleration, although the more powerful Mercedes-Benz CLS 400d is significantly faster.
In a similar vein, there's also a petrol V6: the 335bhp 3.0-litre 55 TFSI. It's quicker than the 50 TDI (claimed 0-62mph takes 5.3sec compared with 5.7sec), but you have to rev it harder to extract all its performance. Our favoured engine, which strikes the best balance between costs and performance, is the 242bhp 2.0-litre petrol that's badged up as 45 TFSI. Again, you need to rev it hard to get the best from it, in which case it'll officially hit 62mph in 6.2sec, but when you're not revving the bejesus out of it there's enough low to mid-range oomph to deliver comparatively relaxed pace.
That brings us neatly on to our big gripe with the A7. All the engines are smooth, and the A7 is relaxed in terms of wind and road noise — both are very well suppressed compared to the CLS — but its gearboxes, both the seven-speed dual-clutch and the eight-speed auto, can be frustratingly jerky. That's because they're so reluctant to kick down, and when they do, the revs flare up erratically. And because of how slowly they react, even from a standstill, trying to pull onto a busy roundabout, for example, can also be quite a challenge.
The A7 is no sports car, whichever engine you choose. Opt for quattro four-wheel drive and, yes, there's plenty of traction combined with enough outright grip that the Q7 will hang on in corners well. But it's not much fun — it's merely effective. The steering isn't very reactive at the start of turns, and even though it builds weight and reasonable accuracy from that point on, precious little information from the front tyres filters through to the steering wheel to tell you what's going on.
Various suspension options are available; Sport models have passive springs and dampers as standard, while S line versions have stiffened and lowered suspension that helps reduce body roll in corners — and does so quite successfully but at the expense of a firm ride. The optional adaptive dampers give you the option to choose the stiffness of the ride, and would be our recommendation. In the softer settings these allow a supple and calm ride 95 per cent of the time, with only particularly sharp abrasions causing a thump. Dynamic mode tightens everything up when you want to drive more spiritedly.
Optional air suspension is available for the more powerful engines (it's standard on Vorsprung trim). Much like the adaptive dampers this treats you to a wafty high-speed ride but still crashes over really broken surfaces. No A7 jars you as harshly as a Mercedes CLS can, though.
One of the options you might be considering is four-wheel steering. This certainly helps low-speed manoeuvrability in tight spots, but gives the steering an inconsistent feel at other times. Factor in how much it costs and we'd suggest it’s best to leave that box un-ticked.