It may be four cylinders shy of that infamous 12-cylinder oil burner, but the new 4.0L V8 TDI takes a quantum leap forward in efficiency. With 435 hp and a stupefying 664 lb-ft of torque, the SQ7 is not only the most powerful SUV in existence, but it boasts world-first technology to achieve that benchmark. The SQ7 owes its seamless power to a sequential twin-turbocharging system augmented by an electric compressor. You could almost refer to it as a “tri-turbo” setup. The first turbocharger deploys at startup through low and medium engine loads, helped by the electric compressor. The second turbocharger kicks in at higher speeds.
Turbo lag is non-existent, since the compressor virtually eliminates any delay while the turbos are spooling up. Peak torque is achieved as low as 1,000 rpm, propelling the SQ7 to 100 km/h from standstill in 4.8 seconds. The compressor derives its power from a 48-volt electric motor run by energy stored in a lithium-ion battery pack. This electrical subsystem is also responsible for powering the electric mechanical active roll stabilization.
While the SQ7 has enough manners to cruise luxuriously at low rpm around the countryside, tromp the pedal in Sport Mode and it comes alive with a roar. Despite the SQ7 having nearly 300 kg more than the Q7 to lug around, there are a number of reasons – aside from its innovative turbo setup – that it moves so well. Under the lightweight aluminum skin, the stiff chassis makes the SQ7 very stable, as a result it needs less time to recover from hard cornering.
Sending all that power to the road through Audi’s quattro all-wheel-drive system is an eight-speed automatic transmission. Another suite of impressive technology makes the SQ7 as sure-footed as the proverbial mountain goat. The optional dynamic handling package adds a torque-vectoring rear differential that can send extra power to the outside wheels when cornering, greatly reducing understeer. All-wheel steering can turn the rear wheels three degrees in the direction of the fronts, improving its stability and turn-in during high-speed cornering. The same system works to reduce turning radius, by turning the rear wheels in the opposite direction at speeds under 15 km/h. The package also includes the electric active roll stabilization, an ingenious system that can separate the two roll bars into two pieces to provide more comfort over rough terrain, and automatically join them again when the curves require more stiffness.
It sounds like hyperbole, but even through the tight mountain switchbacks, the SQ7 cornered as flat and composed as any sports sedan. It serves notice to competitors Porsche Cayenne Turbo S, the BMW X5 M and Mercedes Benz AMG 63 S.
There are no prices as yet (the SQ7 won’t arrive here until late next year) but expect it to command a 15-20 percent premium over the regular Q7, which starts at $65,000.