Sporty SUVs: Jeep Grand Cherokee SRT8, Porsche Cayenne Turbo, Mercedes-Benz ML63 AMG, Range Rover Sport Supercharged, and BMW X5 4.8i

We were stopped in the middle of nowhere by a river rushing across the road, so we left our cars idling on the wet, patched pavement and stood in the rain to watch it. We were on the back roads of Texas Hill Country, and spring rains had turned many dry creek beds into fast-moving streams and rivers. We'd come here because it seemed like the right place to wring out a cross-section of high-performance SUVs, a distinct mutation of the sport-utility species, one whose lineage we trace back to the original BMW X5. We stood contemplating the churning brown water, but a modicum of good sense--and a healthy fear of ending up on YouTube courtesy of some unseen observer's camera phone--stopped us from trying a water crossing. (Fording attempts claimed the lives of three other drivers in south-central Texas during our visit). Later, the sun would shine on our efforts, as we pushed our five sporty sport-utes along the picturesque and challenging byways that crisscross Hill Country.

BMW added sporty driving character to the sport-utility vehicle for the first time back in 1999. But once the X5 created a new branch in the SUV stream, that stream quickly swelled with entries from Mercedes-Benz, Infiniti, Porsche, Cadillac, Land Rover, Chevrolet, Jeep, Acura, and Audi, all of which have introduced SUVs with some degree of sportiness. (Do we hear some student of the early '90s squawking about the turbocharged GMC Typhoon? OK, but it was pretty one-dimensional, not to mention short-lived.)

The occasion of an all-new X5 struck us as the perfect time to take a fresh look at the idea of the athletic SUV. So we gathered up the new BMW plus a group of performance sport-utilities that spanned a wide range.

The Mercedes-Benz M-class can be made into a sporting machine, but it takes in-house tuner AMG to do it. AMG's tack here is typical of the company's method elsewhere in the Mercedes-Benz lineup: stuff its 6.2-liter V-8 into the engine bay and back it up with wide tires, a stiff suspension, and massive brakes.

The fact that Porsche entered this field says a lot about how popular--and profitable--it is. The Porsche Cayenne was codeveloped with the Volkswagen Touareg and is now also related to the Audi Q7, but the Porsche is undeniably the sportiest of the siblings. We chose a Cayenne Turbo to push the idea of a Porsche SUV to its logical conclusion.

Coming from the other direction is staid old Land Rover, which earned its street cred in sub-Saharan Africa but nonetheless felt the need to give its nose-in-the-air Range Rover brand a model designed to whip around corners as well as tiptoe down hillsides. We specified a supercharger for our Range Rover Sport, because without it, the last part of the name is a bit of a misnomer.

Finally, we threw an American wild card into this Eurocentric mix. Both Chevrolet, with its TrailBlazer SS, and Jeep, with its Grand Cherokee SRT8, make muscle-truck versions of their mid-size SUVs, but the TrailBlazer's less-potent V-8 and crude four-speed automatic made the Jeep the easy pick to carry the U.S. flag on our foray into the Lone Star State.