AT THE comfort end of the premium SUV world sits the imperious Range Rover. At the sports level sits the harder of the Porsche Cayennes. Others slot in at points between the two, with mixed success. Nobody dreamed of doing both things equally well at the same time — until the Audi SQ7’s technology came along.

Car makers usually prefer their new technologies to be in your face, if for no other reason than to remind you why you upgraded and to show you “see, haven’t we been busy?”

Usually, but not always. The SQ7 isn’t like that. It delivers probably the biggest step-change in technology the luxury SUV world has seen in decades, but you wouldn’t know it unless you went looking for it.

When it arrives here in the fourth quarter, you’ll find an SUV that seats seven, gallops quickly and urgently in a straight line, sounds good and is whisper quiet. It also promises to ride like a Range Rover and handle every bit as well as a Cayenne or an X5M. Maybe even better.

It’s one of the most complete, coherent, all-purpose machines money can buy.

There are a select few big SUVs that corner reasonably well (because of the limitations of mass). But in the context of the best of them, the SQ7 is a peach in the winding bits.

Then it’s a peach of a thing again on broken tarmac at low speeds (you know, like most of the cities we live in). And that’s before we talk about how fast it is in a straight line, and how smoothly and cleverly it delivers its engine’s 900Nm of torque.

In a dazzling array of new technologies, two of them stand out on the SQ7.

First, it introduces a new kind of anti-roll bar. Instead of each axle having an anti-roll bar linking one side’s suspension to the other, the SQ7 effectively gives each wheel its own anti-roll bar, so the ride can be wonderfully soft. When it needs to stiffen up for hard cornering work, it stiffens to almost become a traditional anti-roll bar again.

This all happens because instead of solid or tubular anti-roll bars across the car, the SQ7 uses one shorter anti-roll bar at each corner, then pairs up the front and rear bars together via small electric motors. These motors each use a three-stage planetary gearbox that separates the torque tubes one side of the electric motor from the other. The gearboxes help the tubes to twist against each other with up to 1,200Nm of torque in faster driving, but are disconnected when the car is cruising to improve the ride quality.

Besides being new, it’s also lighter and smaller than mechanical anti-roll bar systems, and it is governed by the same computer that makes all the decisions for the active dampers, the air springs, the sports differential and the four-wheel steering.

The new 4.0l V8 diesel engine gets a pair of turbochargers, sitting inside the hot-vee. Then it sort of gets another one. Technically, what it gets is an electrically-powered compressor to force-feed air through mechanical turbochargers when they are not already working hard.

The compressor, which spins with up to 7kW of power, can hit 70,000r/min within a quarter of a second after a standing start and Audi claims it’s the thing to have to eliminate turbo lag and to drastically shrink spool-up time from idle.

Those aren’t the new motor’s only tricks, though. The fuel is now delivered at up to 2,500 bar, and it is the first diesel engine to use Audi’s variable valve timing and lift system.

There’s more, but that’s the basic step-change stuff covered. The result is 320kW of power and 900Nm of torque, delivered in a flat line from just 1,000r/min. It thumps through to 100km/h in 4.9 seconds and Audi reins it in at 250km/h.

While it is not the strongest Q7 (the old, rare, 6.0l V12 TDI had 1,000Nm), it is easily the most sophisticated.

Audi targeted the performance figures of the Range Rover Sport SVR and, to understand how well it has done, consider that the SQ7 is 0.1 seconds slower to 100km/h than the fastest Rangie, but with 194g/km of CO2/km, it slashes the British car’s CO2 emissions by 100g.

Its look is more purposeful than the unfortunately styled stock Q7, with a dark grille, bigger air intakes and four rectangular exhaust pipes lurking beneath the subtle roof spoiler.

The interior is as luxurious as you would expect, building off the excellent stock Q7 cabin with its Virtual Cockpit digital dashboard and adding quilted leather seating and higher quality materials throughout.

While pricing has yet to be confirmed for SA, expect it to be priced like either a very good luxury car or a very good performance car. The SQ7 is an excellent version of both breeds, rolled into one hefty package.

Its engine is disturbingly quiet in standard mode, starting in a deep whisper and never rising to great heights of menace, but delivering solid, smooth, sharp performance without ever intruding on the cabin.

The sport mode brings the exhaust into play, changing it to a shorter pipe and amplifying it through the cabin. Still, it’s not as loud as we hoped for inside, even if the tone is more aggressive and the entire performance feels more urgent.

Audi claims the new compressor eliminates turbo lag. In reality, the actual lag people feel in a modern SUV is more likely to come from the eight-speed automatic transmission stepping down from a cruising gear to a punching gear. But what the compressor actually does can still be felt, in three distinct areas of the car’s performance.

First, when you step on to the throttle at the traffic lights. Do that with any kind of authority and the SQ7 simply jumps, with no hesitations, until the tacho needle reaches 1,300r/min or so, then it hammers ahead. There’s no waiting for the turbochargers to spool up. It just responds to the call and huffs, with the V8 bellowing (much louder from the outside than it is inside).

Then you feel its work mid-corner, in the sport or manual modes, when you’re after finely controlled throttle inputs to balance it or to accelerate out of a bend. Instead of giving you not-enough, then too-much, it just gives you what you ask for in a way that feels almost normally aspirated in its linearity.

The next big area where it’s noticeable is cruising on motorways. There, if you need to accelerate from a normal cruising pace, it gives the engine so much more performance at low revs that it usually doesn’t need to come out of the overdriven eighth gear. That improves economy and one less downshift never hurts the cabin’s serenity.

It’s a magnificent engine and does magnificent work, spinning out to about 5,300r/min before it shifts up to the next gear and cruising at around 1,350r/min at 100km/h. That’s right in the heart of the engine’s meat-cleaver zone, which starts at the 1,000r/min torque peak (it runs through to 3,250r/min) and continues through until the end of the 320kW power peak, which runs from 3,750r/min to 5,000r/min.

There’s no feeling, though, of a sudden wave of flat torque and then nothing. It pulls hard to the redline, feeling a lot less like a diesel engine and a lot more like an offshore powerboat racer. There’s a linearity to the way it works that rewards revs. It’s also happy to lurk in its lower speeds, twisting everything out of the way through torque alone.

It’s the gearbox that has the lag now, not the turbo motor, and it has an occasional clunky downshift in the sports mode to demonstrate the strain it’s under. Usually, though, it’s slick and clean in its work.

Its ride quality is also fabulous (though we can’t speak for SQ7s that don’t have the trick anti-roll bar system). There is the occasional nibble from the ultra-thin tyres (285/35 R22) on sharp bump strikes, but you could comfortably iron most of these out by sticking with the stock 20-inch boots or compromising with the 21s. Or you could just live with it, because the nibbles never trend towards uncomfortable. They’re just letting you know there’s something underfoot.

Otherwise, the body control is sensationally clean and good and it moves about with a combination of grace and dignity and sheer togetherness.

It is disdainful of things like speed bumps or ugly potholes, neither of which leave more than a faint ripple on the surface of water in a bottle, and there is none of the lateral head-toss over mild bumps that is the bane of the drivers of most fast SUVs.

Audi also insists the SQ7 has no understeer. From our test, we can’t confirm that there is no understeer, but we can confirm that we never found it.

There are times when you can feel the weight hampering the SQ7, but they are rare, like when you are flicking it through a fast direction change at speeds an MX-5 club racer might balk at. Other than that, it feels like a car that’s 30cm lower, at least 500kg lighter and no bigger than an A6.

It shrinks around the driver whenever it finds corners, with the suspension hunkering down in a remarkable way that both instils confidence and, by keeping the body roll to a bare minimum, retains its dignity.

There’s a phenomenal coherence to the way it behaves in the bends in sport mode, with the steering feeling about right for speed and weight.

A tightening radius bend, normally the curse of the hefty SUV, is dispatched with disdain, with the instant throttle response helping to tuck the nose back in to the later, sharper apex. Savage mid-corner bumps neither unsettle the connection the tyres have on the road, nor toss the cabin’s occupants around in their seats.

It’s as though the car’s cruising speed dignity and calmness simply refuses to go away when the driver is picking up the 2.3-tonne machine and hurling it at a mountainside pass. It feeds the weight transfer across the car beautifully, always keeping the driver informed about how much grip is left (its answer is always “more”) and making the impossible seem easy.

It’s difficult to see how you would crash one of them, except on purpose. Even that is a difficult ask, with 24 standard assistance systems that include lane departure warning, autonomous braking, parking cameras and a watertight skid-control system that’s backed up by astonishing levels of mechanical grip.

But the outright grip and the ability to elicit speed in any corner, in any circumstance, is one thing. It’s fun, it’s stable and it’s a fantastic feat of engineering, but it’s not how you’re going to drive it every day.

Instead, the impression it leaves you with is one of so many complex technologies working hard in seamless harmony to impart a wonderful grace-and-pace feeling of dignity and quiet, confident serenity to everybody in the cabin. It promises to be one of the special ones.