Tough Luxury; C3 offers both in what could be a new truck trend.(GMC Sierra C3)(Brief Article)

If you want to see the future of the full-sized pickup, have a look at the GMC Sierra C3.

Like its SUV and minivan cousins, the standard, garden-variety pickup is getting more car-like with every model year. Look closely at the C3, for example. It has the increasingly popular four doors, leather everywhere inside, OnStar, a 30-channel Homelink transmitter and power everything.

But look under the C3 and you'll see a viscous center differential in place of a manually operated transfer case. A feature once reserved for some minivans and a handful of passenger cars, the viscous differential makes C3s like our test vehicle ``all-wheel drive'' instead of what was once generically termed ``four-wheel drive.'' Owners loved the automatic character of the new differential, which provides full-time four-wheel grip with no input from the driver.

Granted, the C3 is just one of many variations on the full-sized truck theme available from GMC and Chevy. Traditional four-wheel-drive systems with big, meaty transfer cases are still much more common in the lineup. But the C3 is the one out there on the luxury end of the scale trying new things that may someday trickle down to the full line.

Despite GMC's bragging about the C3's ``Performance Biased Driveline,'' its suspension performed no better than most competitors in our 490-foot slalom. Despite a claim of ``a level of poise unprecedented in half-ton pickups,'' the C3 managed only 38.8 mph through the cones. The Ford F-150 got 39.28 mph, the Dakota ...