What is it?
It’s our first UK drive of yet another physics-bender from Audi, this time allying the five-metre, 2.4-tonne heft of the seven-seat Q7 SUV with the accelerative promise of the ‘S’ sub-brand. The well-received SQ5 - powered by a 322bhp, 3.0-litre bi-turbo diesel V6 - is a scorcher at 5.1sec to 62mph, but its big brother is quicker still at an arguably unnecessary 4.9sec.
It's all thanks to a new 4.0-litre V8 engine with a pair of sequential turbos and a 48V blower officially called an electric power compressor (EPC). A new variable valve system orchestrates how the three turbines interact. This hardware conspires to make a fulsome 429bhp and - brace yourself - 664lb ft of torque that’s available from a barely awake 1000rpm.
The pioneering, 48V lithium-ion electricity supply also powers the active anti-roll bars that are packaged with all-wheel steering and - for the first time in a Q7 - a torque-vectoring rear differential in the optional £5700 Driving Dynamics Sports Pack, as fitted to our test car.
Air springs and adaptive Sport dampers come as part of the £70,970 base price, however, as does an active exhaust, 20in alloys, Audi’s widescreen 12.3in high-res LCD driver's display, upgraded leather and a reversing camera. All this comes on top of the already convincing S line kit list.
What's it like?
Truly, madly and irresistibly rapid. Big-cube, multi-cylinder diesels that disgorge fat slabs of torque without breaking a sweat are par for the course, but the amount of shove and the alacrity with which it’s delivered by the SQ7 is next-generation stuff.
The EPC’s effect isn’t instant, but it takes just 0.25sec for its turbine to hit 70,000rpm, meaning if you floor the throttle at 1000rpm while dribbling along in fourth, all hell has broken loose by the time you reach 1100rpm. The turbos - the smaller one for light/medium loads and a bigger one for the heavy duty stuff - operate with an efficiency that allows near-unfettered expedition all the way to 5000rpm, and nigh-instant access to it at any point along the way.
The eight-speed Tiptronic torque converter gearbox is plenty quick for this application, wrangling the huge torque delivery with a passive robustness that responds swiftly to paddle shifts and smartly enough to kickdown requests, which are usually answered with decisiveness.
There’s a suitably aggressive soundtrack, too, with a demonic burble at idle that rises in volume and potency with the tacho needle. It’s embellished by the cabin speakers, but the noise is enjoyable nonetheless, and can be hushed to a much calmer and sustainable tone by disabling the Dynamic engine sound mode.
But you might want to keep the volume up, because there’s little else to remind you of the speeds the SQ7 reaches and maintains with startling indifference. With the Driving Dynamics Sports Pack fitted, that uncanny composure extends to fast cornering, too. The car turns in swiftly and remarkably flat as the active anti-roll bars brace, bringing a stiffened stability that feels a little odd but means you barely have to ease the throttle. The steering is devoid of feel, but doesn’t have the excessive weighting of some ‘performance’ setups and is steady when cruising.
Body control is tidy, with any float being pleasant rather than detrimental, but there's an underlying firmness that erodes comfort by way of regular jostles and the occasional bang over scars, bumps and ridges at most speeds. Our car’s tyres were only an inch larger than the standard 20-inchers, but emitted lots of road noise, too.
The SQ7’s interior is little different to any Q7’s, which means a smart design, sensible layout, top-drawer finishes and impressive infotainment. Just as important are the acres of space in the second row of seats, even when there are passengers in the third row, which pops electrically out of the flat boot floor to accommodate two kids in comfort or two adults under gentle duress. The air suspension can drop 55mm for easier loading, or rise 60mm for off-road sorties.
Should I buy one?
We’d prefer a Range Rover Sport SDV8 for its breadth of abilities, but it costs £14,000 more before you’ve added any options, and at 6.9sec to 62mph it can’t stay with an SQ7 on the charge. BMW’s X5 M50d is a little cheaper and a little cleaner than the Audi, but slower and smaller, and you can’t combine the compelling active roll control option with seven seats in the X5, either.
So for a niche buyer within a niche market, there’s little to match the innovative, capacious and rocket-quick SQ7 - although its price, edgy ride and staid controls clip its wings somewhat.
Location Cotswolds; On sale Now; Price £70,970 Engine V8, 3956cc, diesel with electric compressor and twin turbos; Power 429bhp at 3750-5000rpm; Torque 664lb ft at 1000-3250rpm; Gearbox 8-spd automatic; Kerb weight 2405kg; Top speed 155mph (limited); 0-62mph 4.9sec; Economy 39.2mpg (combined); CO2/tax band 190g/km, 37%