Defining what an SUV is can be hard nowadays. Plenty of vehicles claim they're SUVs when really they aren't much more than car-based crossovers that carry five people and a small amount of cargo. Thankfully, there are still a few true SUVs that epitomize the segment and that clear up any confusion when these three letters come to mind. We've rounded up a trio of these -- the 555-horsepower BMW X5 M, 500-horsepower Porsche Cayenne Turbo, and 465-horsepower Jeep Grand Cherokee SRT8. We'll call them Super SUVs -- SuperUVs for brevity -- due to their massive amounts of power, high top speed, surefooted stick, and excellent utility.

Not one SUV in this matchup takes more than 4.6 seconds to get to 60 mph from rest. Braking to a dead stop from the same speed happens in less than 115 feet for all three. They haul five passengers and cargo, and tow at least 5300 pounds. Every engine corrals more than 450 horses; the same goes for pound-feet of twist.

Five-, six-, and eight-speed automatic transmissions delegate power to all four wheels via blandly labeled all-wheel-drive systems (BMW xDrive, Jeep Selec-Track, Porsche Traction Management). A bit of soft-roading is well within their limits. If you told me these statistics a decade ago, I would have smiled politely and pressed the little red button under my desk. Security will be here shortly...

At a minimum price tag just under $61,000 for the Jeep Grand Cherokee SRT8, and with a best EPA-rated highway fuel economy rating of 22 mpg produced by the Porsche Cayenne Turbo, the players are neither cheap, nor efficient. We wanted find out if these top-tier SUVs can comfortably travel at entertaining and demanding velocities with hefty loads and all seats filled, so we packed our helmets, hooked up flatbed trailers, and drove into the blazing Mojave Desert toward Willow Springs International Raceway.

The Plan
Before fleeing Los Angeles's clogged arteries, we outlined three evaluative rounds of our SuperUV title fight. Round 1 is the liveability test. We wanted to see how well each functions as a daily driver for commuting and errand-running. During this test, towing and canyon carving were strictly verboten. Thanks to Recaro North America and its ProSeries child seats, we saw how well the SUVs copes with a (faux) kid onboard.

Round 2 was all about testing the SuperUVs' proclaimed towing skills. We scheduled a pickup of three 2210-pound vehicle transport flatbeds, and loaded each with a sporty convertible from each vehicle's respective brand. The Cayenne Turbo got to haul a 2011 Boxster Spyder; the X5 M a 2011 Z4 xDrive35is; and the SRT8 a 2012 Fiat 500C. (Chrysler/Fiat doesn't have a sporty drop top...yet.)

The third and final round was unquestionably the most fun. Since all three love running fast, and given that Jeep proclaims its new GC is "Track Rated" (a play on the brand's usual "Trail Rated" label), our in-house hot shoe and road test editor, Scott Mortara, set lap times on the 1.8-mile Streets of Willow course. Track time in an SUV? Yes, please.

DING! DING! DING! Let the brawl begin.

Round 1: The Rise of the Supermarket Sleepers
The "sleeper" label applies to the $121,000 Cayenne Turbo and $92,000 X5 M. Despite their exuberant MSRPs, both don barely modified guises that attract few second looks from passersby. They look just like their non-turbo counterparts.

The Cayenne's modern Stuttgart snout and sleek profile are too passé and common in L.A. Aside from the italicized Turbo plate, subtle hatch spoiler, and Gatling gun LED headlamps, there is hardly anything aesthetic that makes the Porsche stand out. Although the BMW sports an intake-laden front end, a beautiful Monte Carlo Blue hue, and a squatter stance with extra-wide 315/35-20 rear tires, the specialness of this SUV isn't obvious.

The $61,000 Jeep SRT8, on the other hand, is of a different mentality. One fleeting look is all it takes to understand its gravity. While the Germans were conservative in adding flair, the Americans from Auburn Hills bolted on a heap of LOOK-AT-ME stuff, including fat 295/45-20 rubber at all four corners, extra-bright LED DRLs, and a scooped hood. Nothing else in the Grand Cherokee lineup - or the entire Chrysler range, for that matter -- looks as different, or as sinister, as this SRT8. It attracted plenty of gawking mouths and gas station interrogations, and since the Jeep is rated at 12/18 mpg city/highway, it stops at the gas station happen more often than you think. Some call it gaudy. I call it "bitchin'."

If Johnny Comfort were on the SuperUV bittyball team, he'd play second string. But with tauter suspensions employing traditional coil springs/non-adjustable dampers (Jeep), adaptive dampers (BMW), and self-leveling air "springs" (Porsche), each was livable over multiple commuting days. We preferred BMW and Porsche's distinctly German method of suspension calibration, which combines adequate cushiness and surprising responsiveness, to the Jeep's slightly jarring one-dimensional, non-adjustable Bilsteins. Our numerous passengers did, too.

Porsche's engineers poignantly kept the twin-turbo 4.8-liter's rumbling from permeating the leather-lined cabin at abhorrent levels during normal cruising, yet its muffled purr constantly reminds drivers why it's a good idea to keep a lawyer on retainer. Forgetting the worries of the world beyond its laminated glass is as easy as cranking up the theater-crisp $3990 Burmester audio system. As contributing editor Mark Williams noted, "This interior is most like a sports car and most unlike an SUV."