The Audi SQ7 is a torque monster and the world's most powerful diesel SUV

Tim Pitt
The Audi SQ7 is a big piece of car, similar in size to the A8 limousine

Torque: it’s easy to feel, but difficult to explain. As my physics teacher once told me, “power is the speed you hit the wall. Torque is how far you take the wall with you”.

If you do need to move a tonne of bricks, cemented or otherwise, the Audi SQ7 is the perfect choice. With 664 lb-ft of torque, it could probably shift Hadrian’s Wall to Surrey. To put that figure into perspective, the Range Rover Sport SVR we tested a few weeks ago musters a mere 502 lb-ft.

One reason the SQ7 has so much muscle is that it’s a diesel. A 435hp 4.0­ litre V8 diesel, to be exact. Audi has form here – its previous Q7 V12 TDI was the world’s most powerful production diesel when it launched in 2010. And while petrolheads (why are there no ‘dieselheads’?) may disapprove, engines that drink from the black pump make sense in large SUVs. Witness the SQ7’s 38.2mpg fuel economy, versus just 22.1mpg for the petrol SVR.

There’s also something very clever about the Audi’s motor: a third, electrically­ driven turbocharger, powered by an additional 48v battery under the boot floor. Spinning at up to 70,000rpm, it keeps air pressurised to reduce lag (the delay in engine response while a turbo spools up) when you back off the throttle.

It works, too. The SQ7 feels like a force of nature, gathering speed with an urgency that feels unnatural in a 2.3­ tonne 4x4. Turbo lag is truly a thing of the past. Perhaps the biggest surprise, though is the soundtrack. At low speeds, it rumbles and growls like a Ford Mustang V8. Then, as the revs rise, it wakes up with a hard­edged snarl. Your kids will love it – the dog, less so.

One of the benefits of the SQ7, of course, is you can take the whole family along for the ride. Unlike many seven­-seaters, even the third­row chairs can accommodate adults at a push (and a gentle shove). And the interior is finished to Ingolstadt’s usual best-­in-­class standard, with every surface wrapped in leather, suede or brushed aluminium.

Audi’s Virtual Cockpit still has plenty of wow ­factor, too. A 12.3­inch display behind the steering wheel replaces the traditional dials, and can be configured to show the navigation map. A £600 option, it really should be standard on a car costing just north of £70,000 – but then Audi has a knack for pricey extras. Even rear side airbags will set you back £350.

There’s no escaping the Q7’s sheer size – its footprint is similar to Audi’s A8 limousine – but the £1,100 rear­wheel steering fitted to our test car improved manouevrability around town. The SQ7 also acquitted itself well on French mountain roads, thanks to anti­roll bars that uncouple on bumpy surfaces to soften the ride, then reconnect instantly as you round a corner. Amazingly, the electric motors powering them produce 885 lb-ft of torque – even more than that thunderous engine.

If you want sensible buying advice, the regular 218hp Q7 3.0 TDI does about 90 per cent of what the SQ7 can for £22,000 less. Nonetheless, there is something beguiling about Audi’s flagship 4x4. It’s utterly effortless, and surprisingly sporty, to drive. Yes, a Porsche Cayenne still pips it for B­road prowess, but the SQ7 counters with a nicer cabin, better fuel economy and seven seats. Unless you live in Dubai (or have a no­-questions­-asked company fuel card), this slightly ­deranged diesel is the new performance SUV to beat.