In 1997, Lincoln took the wraps off its first sport-utility ever. Dubbed the Navigator, the new luxury SUV amounted to little more than a Ford Expedition (itself a station wagon version of the F-Series pickup truck) with a softer riding suspension, acres of glitzy chrome exterior trim, an ultralux cabin and a sticker price, when fully loaded, of $50,000. Critics predicted a flop.

Instead, the Lincoln Navigator became a sales success, finding popularity with folks who wanted the prestige of a luxury nameplate and a full-size SUV all at the same time. General Motors was prodded into action and immediately dressed up a Chevrolet Tahoe with leather, wood, chrome and a Cadillac badge to combat the threat posed by the Navigator. The Lincoln and the Cadillac were larger and less expensive than the next nearest competitor, the Lexus LX 470, making them all the more attractive. Over time, Lincoln improved the original by bumping horsepower and torque, but it wasn't enough to hold off new and improved competition from at home and abroad. For 2003, Lincoln completely redesigned the Navigator and addressed many of the original design's shortcomings, including the Expedition-clone interior, sloppy handling and tight third-row seat accommodations.

In the process, Lincoln retained signature styling cues while adding neat convenience features like power-retractable running boards, a power liftgate and power-folding third-row seats. Available DVD entertainment in the back and a navigation system keep the vehicle abreast of the current techno toys, and the cabin is artfully rendered with a dual-cowl design reminiscent of Lincoln vehicles built in the 1960s. Last year the Lincoln Navigator received a more refined version of the 5.4-liter V8 engine, though it still produces the same output as before -- 300 horsepower. A significant addition, though, was a new six-speed automatic transmission. Power is adequate for most driving situations, but unimpressive next to the more powerful Escalade. Still, when it's time to haul the family, the 2006 Lincoln Navigator comes through, as it offers plenty of room in the second and third rows -- enough so that a road trip with six adults is actually a legitimate proposition.

The full-size Lincoln Navigator SUV is available in either Luxury or Ultimate trim. Luxury models come with leather upholstery, automatic dual-zone climate control, an in-dash six-disc changer, a roof rack and power-folding side mirrors. Still not satisfied? Opting for the Ultimate sets you up with heated and cooled front seats, a power liftgate, power-folding third-row seats and a power moonroof. Options for both trim levels include a 40/20/40 second-row bench seat (in lieu of the standard captain's chairs), a DVD-based navigation system, a THX-certified audio system, a rear-seat DVD entertainment system and a Class III/IV tow hitch. Power-deploying running boards, a signature Navigator feature, are also available.

The Lincoln Navigator is powered by a 5.4-liter V8 engine rated for 300 horsepower. A six-speed automatic transmission is standard. As the Navigator weighs almost 5,800 pounds, acceleration is adequate but certainly not brisk, and fuel mileage leaves something to be desired. As with other truck-based SUVs, buyers have a choice between two-wheel drive (rear-drive) and four-wheel drive. Properly equipped, the Navigator can tow up to 8,600 pounds.

The Navigator comes standard with side curtain airbags and four-wheel disc brakes with ABS, Electronic Brakeforce Distribution and BrakeAssist. The AdvanceTrac stability control system, which features Roll Stability Control to help reduce the chance of a rollover accident, is standard on all models. The Lincoln Navigator earned a perfect five stars in frontal crash testing conducted by the NHTSA.

Acceleration is adequate in most situations, but when pushed on the highway, the Lincoln's V8 runs out of breath more quickly than its Cadillac rival. Although not as plush-riding as the Lexus LX 470, the 2006 Lincoln Navigator has a composed, confident feel on the road, and body lean is well controlled around corners.

The shapely dash has a dual-cowl design evocative of a 1961 Lincoln Continental and a pleasing blend of warm and cool tones. The sparingly applied walnut trim is convincing, and the leather upholstery is of high quality. Unfortunately, a closer inspection reveals a number of cheap plastics, and some of the controls are hard to use. The Navigator makes no such compromises when it comes to hauling passengers, though, as its third-row seat offers superior legroom -- giving it a usable capacity of seven or eight people. Cargo capacity ranges from 18.3 cubic feet with all the seats in use to 104.8 cubic feet with all rear seats folded down.