By: Dave Abrahams
Ingolstadt, Germany - Audi's SQ7 TDI performance SUV, introduced this week in Europe, has arguably the most sophisticated turbodiesel yet offered in a production car.
The all-new 3956cc BiTDI V8 has reversed cylinder heads, with the injectors on the outside and dual sequential turbochargers nestled in the vee - as well as a third, electrically powered compressor between the intercooler and the inlet manifold.
Snow surprise as we try all-new Q7
It also has a new valve system with sequentially timed camshafts; at low revs only one inlet and one exhaust valve per cylinder are operated, driving just the low-range turbo and keeping gas velocities high.
As the revs - and the load on the engine - rise, the second inlet and exhaust poppets come into play - but the high-range exhaust valves have their own, separate ports feeding the high-range turbo.
And then, at any time when instant response is called for, the 48-volt motor in the electric compressor springs into life, spinning up to 70 000rpm in less than a quarter of a second, effectively negating turbo lag. While acknowledging the electric supercharger of Kawasaki's H2 flagship musclebike, Audi claims this one as the first on a four-wheeled production vehicle.
All of which is good for a quoted 320kW and 900Nm, taking the biggest - although not the heaviest - body in its class to 100km/h in a tyre-shredding 4.8 seconds and on to an electronically limited 250km/h. Nominal fuel-consumption under NEDC laboratory conditions is quoted at 7.4 litres per 100km, CO2 emissions at 194 g/km.
LEVEL WITH THE GRAVEL
Drive is taken to the quattro permanent all-wheel drive system via a redesigned eight-speed tiptronic transmission with built-in self-locking centre differential.
Also new is the optional electromechanical active body roll stabilisation, with a compact 48-volt electric motor and three-stage planetary gearbox separating the two halves of each anti-roll bar.
On rough surfaces - particularly off road - they're allowed to move freely against other for maximum articulation and improved ride comfort. At high speeds on tar however, the electric motor actively jacks up the outside wheels, significantly reducing body roll and understeer. By verying the current to the motors, the effect at front and rear can be adjusted independently for scalpel-sharp steering.
The 48-volt power supply for the electric compressor and the body-roll stabilisation system cones from a 48-volt lithium-ion battery with a 470watt-hour capacity and peak output of 13kW, charged by means of a DC/DC converter from the car's conventional 12-volt generator.
BELLS AND WHISTLES
Electromechanical power steering, all-LED headlights, drive select driving dynamics, specially tuned adaptive air suspension and 285/45 gumballs on 20 inch rims are standard; rim sizes up to 22 inch and lightweight carbon fibre-ceramic discs will soon be offered as options.
The optional matrix LED headlights have 30 LEDs each paired with three reflectors.
Also an option is a driving dynamics package comprising the roll stabilisers, a sports rear differential and all-wheel steering, which turns the rear wheels up to five degrees - in the same direction as the front wheels at low speeds to reduce the turn radius and make parking this big (5070mm long) SUV easier, and the other way at high speed for quicker steering and increased stability.
The seven-seat SQ7 comes with your choice of standard sport seats and optional sport seats plus, with sliding/folding second-row seats for access to the third row, which can be electrically folded flat for extra luggage space, behind a standard-issue electric tailgate.
VIRTUAL COCKPIT
The SQ7's 12.3 inch instrument panel is configurable from the multi-function steering wheel, as is the optional head-up display, while the standard MMI system includes a large glass surface on the centre console give you a haptic confirmation of every click.
The SQ7 TDI options list includes no less than 24 driver assistance systems, including adaptive cruise control with traffic jam assist.
It even uses navigation data to slow you down before you can see the new speed limit signs, for instance when coming off the open road into a town - a feature that seems tailor-made for South Africa's national roads, where it will be released in the fourth quarter of 2016.