The new Range Rover Sport is Land Rover's first shot at the burgeoning fast-SUV market. To ensure the Sport is what it says it is, the top-of-the-range version boasts a Jaguar-sourced supercharged V-8 underhood kicking out 390 horsepower (the entry-level model gets the same 300-horse, 4.4-liter naturally aspirated version of the engine as used in the LR3). Land Rover is clearly targeting the BMW X5 for pavement athleticism, but claims far more off-road ability. The RRS's top speed is pegged electronically at 140 mph, the limit of off-road-tire technology. And yet, with extensive use of electronics and clever suspension hardware, as well as such traditional SUV items as a low-ratio transfer box, Land Rover claims the Sport can reconfigure itself at the flick of a couple of switches from fast-road handler to trailer hauler to serious off-road explorer.

Despite its nameplate, the Sport is derived from the all-new, Motor Trend Sport/Utility of the Year-winning Land Rover LR3, a very different bloodline from the Range Rover's. But the Sport is a lot more road-focused than the LR3, or the Range Rover itself, because of important changes to the hardware and computer programming.

Hardware first. Compared with the LR3, the Sport's wheelbase is nearly six inches shorter at 108 inches. It's a strict five-seater, without a third row. It also rides lower on its suspension, though the layout is similar: control arms all around, with air springs and self-leveling. It runs bigger, lower-profile tires.

The supercharged version gets a system called Dynamic Response, a powered anti-roll bar that actively resists cornering sway. Cutting the roll is vital to a sporting drive: It means faster steering response and more precision, as well as extra grip because the tires are kept more upright.

The Sport has a variable-rate power-steering system, which means the steering can be sharp in corners without being twitchy at speed in a straight line. The supercharged version also gets significantly upsized four-pot Brembo brakes.

As for software, the steering assistance is electronically speed-variable, so it weights up at speed. There's also a different electronic-control map for the progressive lockup of the center and rear diffs. That means much of the SUV's handling balance is under the control of the engineers: Sensors detect slip and set some lockup for stability, so torque can be channeled to the wheels that can make best use of it. Otherwise, an open diff allows agility, and, thanks to the anti-roll system, there's more grip on dry pavement. The electronic air suspension lowers itself at speed for more stability and improved aerodynamics. Another software tweak: The manual override in the six-speed auto box actually blips the throttle on downshifts for a sportier feel.