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ROYAL FORD

Through rain, dust, and devilish twists

Porsche Cayennes flourish on a tortuous test

UVALDE, Texas -- To stretch (and sometimes exceed) the limits of a car, there is no better toy box than Continental Tire North America Inc.'s Uvalde Proving Grounds, a 5,000-acre site about 80 miles west of San Antonio.

It's where we were recently able to drive Porsche's 2008 Cayenne line on a drag strip, a gravel rally circuit, a dry and twisting road course, a wet and twisting road course, and through a slalom of cones on a long stretch of pavement.

All three models -- the Cayenne, Cayenne S, and Turbo -- put on powerful displays.

Just as significantly, they also proved to be remarkably stable, with upgraded control systems that are bolstered by Porsche's new Dynamic Chassis Control .

The base V-6 engine is up to 3.6 liters and has 290 horsepower. It can be mated to a manual six-speed transmission, and a six-speed Tiptronic is optional.

The V-8 in the Cayenne S is now a 385-horsepower beast that is only available with the Tiptronic.

But the real monster in the fleet is the twin-turbo V-8 with 500 horsepower -- also available only in Tiptronic.

Direct fuel injection is part of the magic behind the new engine lineup. Porsche claims it actually helps cut fuel consumption while boosting power. But it is difficult to test consumption when flogging a car around various types of race tracks.

Stability management for the Cayenne models was introduced for the 2003 model year, and rollover sensors to tighten belts and deploy air bags in an emergency have since been added. But the chassis control system costs an additional $3,500 plus another $3,000 for an air suspension system to make it work. That makes it an expensive package for anyone who isn't a driving enthusiast.

But, oh my, I could feel it on the slalom course. When I put an earlier generation Cayenne through its paces I could see the roll of the windshield pillars. In contrast, a model equipped with the new chassis control sat absolutely flat during the same exercise.

The system uses a series of motors and pressure lines to monitor and control anti roll bars front and rear. It senses when a side or corner of a Cayenne is about to give in to the force of a hard turn, and uses pressure to keep it from dipping. At low speeds it will also let the front and rear suspension spring free to allow for the flop-and-reach that is often required under those conditions.

The combination of stability control and the new chassis system was invigorating on the gravel rally route. The car could be driven hard into even the sharpest of corners. In a fashion many professional rally racers would admire, it let the tail slide far out as the car was pushed through a corner, but not too far.

It was the same on the wet road course where a constant spray of water approximated driving a tortuous route in a downpour. Again, it was easy to sense when the system became smarter than the guy behind the wheel.

On the dry road course, screeching tires meant we were at the edge of performance, but not in danger of going over it.

To all but the most knowing Porsche fanatics, you would probably have to park the new Cayennes next to an old one to notice the exterior changes. But then they become obvious. Most apparent is the longer, more sculpted band of the headlights, which reach out to give the hood a wider line and emphasize the bulge of the front fenders over the tires. The exaggerated fender bulge, a trademark in the sports car line, is more pronounced in the rear, where the twin exhaust pipes are enclosed as they emanate from the bumper.

Four years ago, many Porsche fans complained that the company was building an SUV. Today, with a four-door sedan on the horizon, I would argue that such diversity has helped Porsche AG remain successful and perhaps even stay independent.

Royal Ford can be reached at ford@globe.com.

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