In effect, the electrically driven compressor – we might get used to calling it an EPC, or we might start, perhaps incorrectly but rather more conveniently, come to know it as an electric turbo – is said to reduce lag to negligible levels. It and the roll bars need to be 48V because they require enough oomph to act quickly and powerfully, and the only ways to get more power are to increase current or volts – and more current requires bigger hardware and thicker leads, so volts it is (there’s a 48V lithium ion battery in the boot). Thus driven, then, the motor fills a gap in the torque curve left by the other turbos as they spool up at lower engine revs, although later on in the rev range they take over in sequence and do the hard blowing. First a small one blows, then a bigger one takes over. At some point a valve in the exhaust lets out more noise, too.
All of which results in one of the most impressive set of engine stats in motordom: from 1000rpm you can have 664lb ft (the same as a 6.0-litre W12 petrol-engined Bentley Bentayga makes from 1350rpm), and not long after peak torque subsides -3250rpm - peak power arrives. That’s 429bhp at 3750rpm, which remains in situ right to the 5000rpm red line. There was a time when the more relatively powerful the turbodiesel, the boostier and narrower the delivery. Not any more. This has a broader spread of shove than the engine they’ll put in Boaty McBoatface.
That’s quite enough about the motor for now, though. As standard, the SQ7 gets sportier air suspension than regular Q7s in order to make it worthy of the ‘S’ tag. The active anti-roll bars are, however, an option, as is four-wheel steer, a limited-slip rear differential, ceramic brake discs and alloy wheels up to 22in in diameter. Perhaps Audi forgot that this is a 2405kg SUV, not a sports coupé. Anyway, as you’ve probably guessed, the car we were loaned contained all of the above. Elsewhere the SQ7 is a Q7 – a big, imposing, seven-seat SUV.
What's it like?
Well, if it’s not the best-sounding diesel engine in production, I don’t know what is. There are hints of muscle car, powerboat and freight train, and that has to count for something. It’s also obscenely fast and, in doses, more entertaining than you’d credit.
More helpfully, though, the SQ7 is refined. It’s an extremely quiet car and one that never feels that tall. Catch it in profile and it’s more crossover than SUV. The design helps, with those high window lines making even a tall driving position feel lower than it is.
Fit, finish and ergonomics are good, as is interior space, and there’s plenty of entertainment and information kit even as standard. Add to all that the easy way it cruises and a compliant ride, even on those 22in wheels, and you can imagine covering lots of miles with precious little effort in an SQ7.
There are different driving modes – of course there are. Some stiffen the suspension, firm up the steering, give more exhaust noise and sharpen the drivetrain response. Or you can pick and choose, and I would. Audi had set the test cars up to ride comfortably, with easy controls, but maximum noise and response. The combination suits it.
Even in Comfort mode the SQ7 retains fine body control when wound right up. Those active anti-roll bars do good work, slackening in a straight line and firming in corners. No 2.4-tonne, 1741mm-tall car is as dynamic as an ‘S’ badge would have you believe, regardless of its diff or 22in wheels, but it hides its weight admirably well (until you smell the brakes) and holds a line more tightly than I think a Bentayga does. The steering, which is accurate enough but curiously uncertain of weight, is less pleasant than the Bentley’s though. Or a Range Rover’s. Or a Volvo XC90’s. Or a BMW X5’s.