America seems to have an insatiable appetite for upscale SUVs right now, and big, gussied-up utes derived from a full-size pickup turn out to be the most profitable automotive product on the planet. So what's more logical than taking the old Chevy Tahoe/GMC Yukon, bolting on a new face, tossing in luxury features and marketing it as a four-wheel-drive limo for the well-heeled?

Enter the GMC Yukon Denali (and its dolled-up sister, the Cadillac Escalade). Exterior styling differs from the donor previous-generation Yukon by the use of more distinct sheetmetal from the hoodline forward, plus a bold rectangular center-port grille. Reflector-optic halogen headlamps and recessed projector-beam foglamps reside in a smoothed-out front fascia. Body-color cladding and integrated running boards spruce up the flanks, with textured body-color door handles, outside rearview mirrors and color-keyed rails on the flush roof rack completing the monotone look. Out back, a functional step bumper conceals a standard trailer hitch.

The Denali's interior boasts upper and lower consoles packed with storage cubbies and features such as reading lamps, cupholders, a rear power point and audio controls. Instrumentation is backlit in blue with white pointers and includes a tachometer. Luxury touches abound, with Zebrano wood trim, leather front and rear heated seats, and a premium Bose sound system. GM's factory-installed OnStar mobile communications system is now standard equipment.

Powering all this opulence is a 5.7-liter pushrod V8 packing 255 horsepower. The Vortec 5700 puts its 330 pound-feet of torque to the ground via a four-speed automatic transmission and the Auto Trac full-time four-wheel-drive system. When activated, the Autotrac transfer case will automatically shift from two-wheel drive to 4WD when it senses wheel slippage. Denali rides on unique six-spoke chromed aluminum wheels wearing Firestone 265/70R-16 touring tires designed especially for sport-utility applications on- and off-road in both wet and dry conditions.

Available in an array of exterior colors, the Denali provides a ''look-at-me'' driving experience around town and a king-of-the-road feel out on the highway. Frankly, you expect a lot from a truck with a $40K-plus price tag. But understand that it is all riding atop a pickup platform that is more than a decade old. That means this truck has all the flaws inherent to its humble underpinnings, such as sloppy steering, numb brakes and unrefined ride. What's worse is the use of GM's previous-generation interior plastics, which simply aren't in keeping with Denali's price.

For our money, the Denali lost much of its luster when Cadillac literally thieved the whole vehicle from GMC to offer the Escalade. Add in its dated mechanicals, and Denali becomes a tough sell.