It's one thing for BMW and Porsche to offer high-horsepower track runners, but when Jeep, the guardian of all things 4x4 trail-rated, decides to offer a monster street performer that's quicker and faster than the hi-po X5 or Cayenne Turbo, there must be more to the story. In fact, one of the fastest-growing segments in the industry right now is the premium performance-SUV market. Even Land Rover is getting into the act with its Range Rover Sport S/C (fully explored elsewhere in this issue). Power and performance are back, and SUVs are getting the full dose.

With the 6.1-liter Hemi V-8 at his disposal and a cautious green-light from Jeep engineers, Dan Knott, director of the Street and Racing Technology group, was given the task of turning on- and off-road performance into something more pavement-biased. The result is a menacing-looking Jeep Grand Cherokee with 415 horsepower and 410 pound-feet of torque running on low-profile W-rated (168-mph) 255/45R20 tires in front and 285/40R20s in back. SRT mad scientists actually lowered the stance of the Grand Cherokee one inch (that may be a Jeep first) and stiffened the suspension with specially tuned springs, shocks, bushings, and anti-roll bars. They even reshaped the front knuckles to allow the vehicle to take a better set when entering corners at high speed. In addition, the electronic stability program is specifically calibrated with the new all-wheel-drive system (heavy-duty case but 60 pounds lighter), SRT-tuned A580 five-speed automatic, and engine, to allow maximum grip and power during "enthusiastic" maneuvers.

SRT-8 Grand Cherokees get 20-inch alloy wheels, up-size brakes (14.2-inch in front and 13.8-inch in back), and a custom dual exhaust that exits a center cutout in the rear bumper. Inside, highlights of brushed aluminum and carbon fiber give the layout a precision-oriented, warm, technical feel, while deeply sculpted performance seats are designed to hold driver and front passenger securely during aggressive turns. And the speedometer reads up to 180 mph. The handful of options offered for the SRT-8 will include a nav system, a Sirius Satellite radio subscription, and Bluetooth technology. If other SRTs are any indication of pricing, look for the 2006 Grand Cherokee SRT-8 package to cost between $7500 and $10,000 extra.