Good: glorious engine, tech, comfort, refinement, quality, space.
Not so good: not actually all that sharp to drive.
Model tested: Audi SQ7
Pricing: €138,074 as tested; Q7 starts at €72,125
Engine: 4.0-litre triple-turbo diesel V8
Transmission: eight-speed automatic, four-wheel drive
Body style: seven-seat SUV
CO2 emissions: 190g/km (Band D, €750 per annum)
Combined economy: 39mpg (7.2 litres/100km)
Top speed: 250km/h
0-100km/h: 4.9 seconds
Power: 435hp at 3,750- to 5,000rpm
Torque: 900Nm at 1,000- to 3,250rpm
Boot space: 235 litres all rear seats up, 770 litres rear pair of seats folded, 1,890 litres all rear seats down
EuroNCAP rating: five stars; 94 per cent adult, 88 per cent child, 70 per cent pedestrian, 76 per cent safety assist
There's big. Then there's bigger. Then there's really big. Then there's a Starbuck's Venti coffee. And then there's a Texas ribeye steak. Above them, more or less, sits the Audi SQ7, big of body, big of engine and most definitely big of character. Here is a high performance SUV not quite like any other.
Why? Because of its choice of engine. Land Rover decided on a 550hp supercharged V8 petrol for its delightfully unhinged Range Rover Sport SVR, but Audi has been by comparison positively sensible with its engine - a 4.0-litre V8 diesel (shared with Bentley) that has a full complement of three turbochargers.
Well, actually that's not quite right. The Audi SQ7 has two conventional turbochargers, which work sequentially for improved low-end and high-end response, but it also has an electrically-driven compressor, which, working from the high-tech 48-volt electrical system, can fire air into the engine without waiting for the speed of the exhaust gas to start driving a normal turbo. That waiting time is, of course, known as turbo lag and the SQ7 doesn't have any.
Instead, it has the same effect as hitting a substantial house with a runaway express train - a lot of mass suddenly moving in one direction. Keep the Audi Drive Select system tuned to Comfort or even Eco mode and the V8 responds instantly with a deep, distant roar and a faint hint of V8 backbeat. That 4.5-second 0-100km/h time seems entirely believable and the big V8 is one of those rare engines that just seems to keep on gathering speed the more you ask for it. The redline on this engine is truly irrelevant - you're going to be so deep into illegality by the time you reach it in any gear that you really just shouldn't bother...
Dynamic mode adds an extra layer of high-rise madness. The steering weights up and the stereo begins to lay on an extra bit of V8 rumble and burble until it sounds more as if you're driving a Dodge Challenger than a diesel Audi. It's really quite lovely.
The thing is that it's actually not all that much fun to throw around. The SQ7 isn't the heaviest car in the class, by a long stroke, but neither is it light and it's sure as hell not small. That's a four-wheeled physics lesson that the SQ7 simply can't sidestep, so while it's far more agile and mid-corner adjustable than any car this big and tall has a right to be, it's just not fun. In Dynamic mode, you can cross country at Exocet speeds, no doubt, and the active roll control system (again, powered by that 48-volt system) keeps all on an even keel, but the steering is too heavy, making you wrestle it more than turn it and there's no actual feedback or reward for the added speed.
You're actually better off keeping it in Comfort or Eco - engine response is barely any less ferocious and the slightly more pliant suspension and steering makes twisty road work less of a chore.
Better yet, in either of those modes and without the fake engine sounds, the SQ7 is one of the most refined, comfortable and silent cars in which you can travel. Our test drive itinerary took in Dublin, Belfast, Malin Head and West Cork and at no point on the journey was the big Audi anything less than incredibly quiet and cosseting. It may be an expensive way of finding some silence (and to be honest a standard V6 TDI Q7 isn't much worse off), but you really will need to break into Rolls-Royce territory to do much better than this.
Of course, the SQ7 has some advantages over even a Rolls. Seven seats, for a start, plus an utterly enormous boot when the third row of seats is folded away. The cabin is a place of exceptional quality and typically thoughtful Audi design - it's not something of which you'd ever tire, I feel, although there is an occasionally annoying lack of places to store small items up front.
It's sure not cheap, and it could be more outright fun, but there's no denying the sheer appeal of a big car with a big characterful engine. Diesel may be doomed, ultimately, but with the SQ7's mighty V8, it's going out in thunderous style.
Alternatives
BMW X6 M50d: not quite as much power or torque to the Audi, though slightly sharper to drive, but the cabin's not as nice.
Mercedes-AMG GLE 63: overpowering levels of torque and noise, and it's big fun, but you can't have the Benz with seven seats, even in non-Coupe format.
Range Rover Sport SVR: petrol thirst is ridiculous and it looks a bit too Wayne Rooney inside and out. Massively good fun, though.