When did sports cars that go 0-60 in 3.7 seconds become so civilized? From the outside, or even inside, an X50-packing Turbo looks no different from a car not so equipped. It idles smoothly (although with a richer, gurglier exhaust note), and the clutch is light and progressive. Mat the throttle, and the X offers nearly the same Saturn V rocket lift-off sensation as the GT2--but in a fashion utterly without drama. This is 30 additional horsepower you can really feel, and the performance increase is clear even without the use of test gear.

Why is the Cayenne 1.7 seconds slower to 60, 5.2 seconds slower to 100, and 17.44 mph slower through the quarter than the also-450 horsepower X50-equipped Turbo? Weight, of course, and, to a lesser extent, aerodynamics. The Cayenne is a porky 5192 pounds, which is a lot for a vehicle this size. But its many electronic and hydraulic systems add mass. The Turbo weighs 3388, so do the math. The Cayenne's power-to-weight ratio is 11.5 pounds per pony, the Turbo's a more racecar-like 7.1.

Are they interchangeable? No. But together, this disparate pair demonstrates the product diversity this company is now capable of. Think about it: For the '03 model year, Porsche gave the Boxster and Carrera trim and power updates and launched the Cayenne from scratch. Let's not forget the new GT3 and Carrera 4S models. A C4S Cabriolet has just hit the market, and a Turbo Cabriolet is on its way. A just-announced, limited-edition GT3 RS recalls a famous 911 nameplate, although it's not, so far, destined for the North American market. And if you thought these folks didn't have enough to do, they've also been wrapping up production development on the Carrera GT hyperexotic.

So: Cayenne or X50-packed Turbo? The well-diversified garage would have one of each.

Porsche Cayenne TurboPorsche Turbo X50
Base price$88,900$116,200
Price as tested$96,090$137,145
Vehicle layoutFront engine, awd, 4-door, 5-pass Rear engine, awd, 2-door, 2-pass
Engine4.5L/450-hp twin-turbo V-8, DOHC, 4 valves/cyl3.6L/450-hp twin-turbo F-6, DOHC, 4 valves/cyl
0-60 mph, sec5.43.7
1/4 mile, sec @ mph13.79 @ 102.4711.86 @ 119.91
Braking, 60-0 mph, ft112110
Skidpad, g0.850.94
600-ft slalom, mph65.969.9
On sale in U.S.CurrentlyCurrently