Road Test: Audi Q7 3.0 TFSI Quattro SE 5dr Tip Auto

This new petrol Q7 is more economical, more modest than the V8 version it replaces. Not a tough task: that car was to modesty and economy what Vin Diesel is to understatement and head-hair.

By the standards of Planet Normal, though, this Q7 - powered by the 3.0-litre supercharged V6 from the S4, instead of that gluttonous, naturally aspirated 4.2-litre V8 - is decidedly immodest and uneconomical. It still makes everything else on the road short of a big-rig truck look like a Corgi model.

And, unless an oil well has recently sprung up in your back garden, it will still provoke a pained wince every time you come to refuel it. Which will be often. The V6 may boast a less prodigious thirst than the old V8 - a car in which recording anything over 15mpg required the self-restraint of a Buddhist monk - but indulge, even fleetingly, in a spot of what the brochures refer to as ‘enthusiastic driving', and you'll be visiting your local service station more regularly than a man with an incurable fetish for barbecue coals and camping chairs. Though Audi quotes a combined economy of 26.4mpg, we struggled to coax the Q7 to anything more than 20.

Maybe that's not surprising, given the sheer size of the thing. This Q7 tips the scales at nearly two-and-a-half tonnes. What's more surprising is the pace at which it shifts. This is a really rapid car. With 328bhp and 325lb ft available, it'll crunch 60mph in under seven seconds - a full half-second quicker than the old V8 - while hiding its heft in a manner that'd make Gok Wan proud. The Q7 tackles corners with the poise and precision of a far smaller, lighter car. The new eight-speed auto - now standard on all Q7s - is a beauty, capable of both inconspicuous shifting or, should the mood take you, rapid-fire flicking between ratios as that fuel gauge drags you ever deeper into financial ruination.

You know what we're going to say here. Get the diesel version. If you're planning on using your SUV for long-distance trips or towing or basically any real-world driving, obliterate this petrol version from your mental shortlist, and opt instead for the lovely V6 diesel - an engine that can at least contemplate the possibility of cresting 30mpg. But think instead of this top-spec Q7 as a big luxury limo - a taller, brasher rival for a Merc S-Class or Jag XJ - and it begins to make some sort of warped sense. If you can live with its fundamental disregard for fuel economy - and, indeed, the feelings of fellow road users - this is a serious bit of kit. Fast, stable, huge and packed with lashings of tech, this Q7is a car with an impressive breadth of abilities. Modesty and economy are not among them.