With all that power, the Turbo Cayenne is a formidable beast, throwing you deep into the seatback. The two inline turbochargers, variable camshaft timing, forged pistons, and a host of other modifications let the Turbo V-8's 450 horses feel like more--the most hard-core Porsche-phile will have to crack a smile. Porsche will also offer a six-speed transmission, including a low 4.15:1 first gear. Even with five other close-ratio gears, shifting up or down the ladder is surprisingly smooth. The Tiptronic six-speed will be standard on all Cayennes and include a computer program that learns driver habits and adjusts accordingly, as well as continuously monitoring whether the vehicle is in a hard corner, on a steep grade, or under full throttle. Staying true to its performance heritage (even with an SUV), Porsche will offer paddle shifters off the steering column as an option. Manual shifting also can be done from the console stick.

The shift lever is flanked by two grab handles that, at first glance, look horribly out of place. However, the handles can be convenient for moving in and out of the vehicle. The Cayenne's cabin is a superb piece of design, with high-quality materials and stitching on par with fine furniture.

The Cayenne's four-wheel independent suspension uses high-strength steel to accommodate hard launches and braking and severe 4x4 duty. Coil springs are standard, with an almost infinitely ride-height-adjustable airbag suspension system available as an option. From full extension to kneeling, its adjustment range is an impressive 4.5-plus inches. This setup is designed to raise and lower automatically as different circumstances, parameters, and driving conditions arise; a center-console switch allows manual control. The air suspension also acts as an active handling system, continuously monitoring each corner during hard and less-aggressive driving/ braking to prevent the vehicle from the typical diving and squatting--and it allows for continuous load-leveling. Thoroughly impressive.

Braking performance is astonishing, via 13.8-inch six-piston Brembo stoppers in front and 13.0-inch four-piston clamps in back. We found the active suspension system incredibly quick to react and able to keep the Cayenne flatter than any SUV we've ever driven, even around hard corners and during panic stops. We were told by renowned rally legend and Porsche test driver Walter Rohrl that the Cayenne ran a tick faster than the BMW X5 and Boxster S around Germany's fabled Nuerburgring. The best time for a Cayenne S (non-Turbo) was nine minutes, four seconds, against the BMW X5's 9:06 and Porsche Boxster S' 9:05 Factory Turbo Cayennes run the Ring at 8:42.

No doubt there'll be both fans and opponents looking to make comparisons between Porsche's first four-door and its seminal sports car, the Carrera. That may not be a bad thing. The Cayenne is exactly what it needs to be, should be, and is expected to be: the best-handling and most-powerful sport/utility on the planet in terms of its on-road performance. Perplexing, perhaps, is that Porsche has gone to great lengths to incorporate bona-fide four-wheel-drive capability, as well. Nobody expects that from Porsche. It may even be argued that nobody really wants that from Porsche.