As recently as 15 years ago, the notion of a full-size SUV that could hit 300 kilometres per hour would have seemed downright absurd. How could a lofty chariot that stands more than 1.6 metres tall and weighs well over two tonnes be that fast? And why?
It’s clearly a sign of progress that there are now no fewer than five high-riding wagons that can crack the triple-century speed limit — Lamborghini’s Urus, Bentley’s BentaygaSpeed, Aston Martin’s DBX 707, Audi’s RS Q8and Porsche’s ballistic new Cayenne Turbo GT.
It’s no coincidence that the Cayenne Turbo GT shares most of its hardware with the Lamborghini Urus and Audi RS Q8, as all three brands fall under the umbrella of the Volkswagen Group and can therefore access many of the same core components.
Be that as it may, each has its own personality and visual presence, with the Porsche offering a different flavour to its Audi and Lamborghini counterparts. Where the Urus is in your face and shouty, and the RS Q8 is a tad understated, the Porsche sits between the two in terms of its stylistic aggression and demeanour.
The new Cayenne spearhead isn’t a GT in name only, as it’s been turned out by the same go-faster Porsche department that has given us cracking sportsters such as the Cayman GT4 and recently launched 911 GT3.
Rather than merely remapping the engine management software, Porsche’s boffins have comprehensively re-engineered the twin-turbo 4.0-litre V8, fitting it with a new fuel injection system and new internals for the turbos and crankshaft. The con-rods, pistons and timing chain are also either bespoke or thoroughly redeveloped for the Turbo GT.
The results are obvious, as a 0-100kph sprint in 3.3 seconds and top speed of 300kph puts the 640hp/850Nm Cayenne Turbo GT in the thick of the hyper-SUV segment. By comparison, the Lambo Urus bolts from 0-100kph in 3.6 seconds and hits 305kph flat out, while Aston’s DBX 707 dispatches 0-100kph in 3.3 seconds and tops out at 310kph.
The GT’s added grunt vis-a-vis the standard Cayenne Turbo means the ZF eight-speed auto and four-wheel drive system had to be thoroughly overhauled, and there’s now an additional cooler for the gearbox’s transfer case to keep temperatures in check.
The Cayenne Turbo GT’s chassis has also been revamped as it sits 17 millimetres lower than the standard Cayenne Turbo, while the air springs and active dampers are retuned to offer 15 per cent greater stiffness. There’s also new software for the active anti-roll bar system and the carbon-ceramic brakes are upgraded. In addition, the 22-inch gold rims and Pirelli P Zero Corsa tyres are bespoke to the GT.
So much for the ingredients. The National’s test confirmed the Cayenne Turbo GT is not only mind-numbingly rapid in a straight line, but also remarkably agile and composed under heavy cornering loads for such a hefty vehicle. The 2.3-tonne SUV’s backroad pace isn’t too far adrift of its low-slung sportscar stablemates, so it somehow manages to virtually defy physics.
Drive the Turbo GT sedately in Normal mode and it’s decently refined, too. Its stiffened suspension and low-profile rubber mean ride quality is firmer than lesser Cayennes. Even so, only the sharpest road-surface imperfections are transmitted through to the cabin. The exhaust gets pleasingly raucous in Sport and Sport+ drive modes, but minus the crackling pyrotechnics you get in the Lambo Urus when you lift off the throttle.
Hugely rapid and capable the Cayenne Turbo GT may be, but you’d still have to ask yourself whether an SUV with only four seats and 549 litres of luggage capacity makes it a better purchase than a Panamera Turbo S sedan. After all, the latter can do pretty much everything the Cayenne Turbo GT can and has the dynamic advantages of being lighter and lower.
Low-profile road-biased tyres and modest ground clearance mean the pricey Cayenne Turbo GT wasn’t conceived to go off-road, but many buyers will nevertheless be lured by its searing pace, lofty driving position and perceived all-terrain capability.
Porsche Cayenne: 20 years on and it still won't slow down — in pictures
