As you’d expect, the RS Q8 is seriously fast, with 0-62mph covered in a scarcely believable 3.8 seconds. That’s quick enough to keep pace with the brawnier BMW X6 M Competition and the far lighter Alfa Romeo Stelvio Quadrifoglio.
Overtaking power is immense, even if you have to wait a beat for the eight-speed automatic gearbox to kick down when you plant your right foot into the carpet. When it does so and you begin to surge toward the horizon, you’re rewarded with a growling V8 soundtrack and a wonderfully bassy exhaust tone.
In order to get all that power down onto the ground, the RS Q8 comes with a permanent four-wheel drive system that has a few additional tricks up its sleeve to shuffle all that muscle around to whichever axle, or indeed wheel, has the most traction at the time.
Clever technology abounds in the standard air suspension, too. There are three different settings: Comfort mode avoids the annoying floaty sensation that plagues some air suspension systems while the firmest Dynamic mode transmits every imperfection to your posterior, but is never truly jarring. In between these modes, there’s a balanced setting that brushes off the worst of the shocks from ridges and potholes.
Even on the most broken stretches of asphalt, we found little to affect the composure of this huge sports SUV, despite the optional 23in alloy wheels tyres fitted to our test car. Comfort and stability are further boosted by active anti-roll bar technology, which disconnects the roll bars on straight roads to eliminate side-to-side sway, but reconnects them in bends to counteract body roll.
The steering is a bit of a revelation compared with the regular Q8, feeling light to begin with, but growing progressively and naturally meatier as more steering lock is applied. You’d never call it feelsome, but it doesn’t suffer from any unpleasant kick-back should you hit a bump partway through a corner. Four-wheel steering is also included to improve manoeuvrability in town and when negotiating tight car parks, and it also increases stability at higher speeds.
When you need to slow things down, the humongous brakes do a great job of scrubbing off speed and resist fade well. Our one criticism concerns the pedal feel when filtering in stop/start traffic. With the effect of the car’s regenerative braking system being incorporated into the initial travel of the pedal, it can feel a little numb and unresponsive, requiring you to push down further than you might expect before the standard brakes kick in. This isn’t a problem when driving at faster speeds, though.
The net result of all this technology is that the RS Q8 does a very convincing impression of a huge but very well sorted hot hatch. For such a big car, it’s remarkably composed in the twisties and, after a short while, your confidence builds in its ability to maintain your chosen cornering arc. There are limits to what it can do, but those will only be encountered during the tightest of turns when taken too eagerly – more an inevitable reality of physics than a shortcoming of the car.