The interior reflects traditional GMC pickup truck thinking. The door openings are now the largest in the industry and the cab is the roomiest. The instrument package comprises a large speedometer and tachometer flanked by four smaller gauges. All use pleasant graphics in white on black. The sound system control panel is located above the climate controls. The climate control system uses a rotary dial layout that works perfectly. There are three 12-volt outlets at the bottom center of the dashboard for radar detectors, cellular telephones, laptop computers, and other accessories. New for 2000 is a programmable door locking feature that can be armed to automatically lock and unlock doors.

Our test truck was an SLE Extended Cab four-door equipped with bucket seats, that provided good support in hard corners. The front seats were equipped with optional heaters. The SLE package comes with a lockable floor console that's large enough to hold a picnic lunch for a family of four; it comes with a reversible, removable cupholder tray and a storage nook in front of the lid. Air-conditioning outlets and a set of drop-down cup holders are built in for rear-seat passengers. A compass is incorporated into the SLE's overhead console, along with three storage areas for sunglasses, garage door opener, and small items. The door trim is a nice combination of vinyl panels and dotted velour that is soft and warm to the touch.

We were pleasantly surprised when we climbed through the new fourth door on the driver's side of the extended-cab Sierra, as the back seat has been redesigned and remounted for far greater room and comfort. With the fourth door, the rear compartment, and the compartment as a whole, seems cavernous, and at least 50 percent more convenient. When cargo capacity is more important than hauling passengers, the entire rear seat assembly can be removed through either of the side doors with a wrench. With the availability of the fourth door, GMC now offers a complete, competitive line of American pickup trucks leaving no advantage to Ford or Dodge.