Another advantage is space. The Navigator is as big or bigger inside than any luxury-class sport-utility vehicle. The driver almost needs an intercom to converse with someone sitting way back in the third seat.

Well, not really. The Navigator is very quiet inside for a truck, and generally quite smooth, almost placid. If you tend to drive conservatively you will probably like this vehicle. Initially, the brake pedal feels a little soft, but it's very progressive in application and easy to master for smooth, even stops, despite a curb weight exceeding 6,000 pounds for all-wheel drive models. With a little practice, the driver can avoid the fore-aft bobbing that can make motion-sensitive passengers feel car-sick.

The Navigator is full of noise-mitigating technology, including acoustically dampened glass in the windshield and side windows. The body boom familiar in vehicles that are essentially big steel boxes, which often comes across as pulses of air hitting the eardrums, is nearly eliminated in the Navigator. The quiet seems to emphasize noise generated by the tires, which is the only noticeable encroachment on the solitude inside. The optional 20-inch wheels and low-profile tires are plain noisy, be it whacking over bumps and pavement joints or just the steady hum of tread on the road surface. Typically, we prefer the appearance of larger wheels, but the price of style is high in the Navigator. We recommend the standard 18-inch wheels and higher-sidewall tires.

The Navigator is as smooth inside as any body-on-frame truck we've tested, and generally free of annoying vibration. The ride is smooth, too (except for the effect of the 20-inch wheels), thanks partly to the fully independent rear suspension. Moreover, the rear suspension helps keep the rear tires pressed to the pavement on bumpy surfaces, eliminating most of that skipping feeling familiar in trucks with solid rear axles. There's no axle tramping over bumps or undulations, and a reasonably smooth driver can keep the Navigator's body (and those inside) nice and level through turns.

Steering is on the heavy side, perhaps surprisingly so in this type of vehicle. The good news here is that, for tracking curves or changing lanes, the steering feels responsive, direct and reasonably quick. The bad? In big, slow-speed turns, such as trying to whip into a parking space, the heavy steering feel can slow things down. Those who like the steering in smaller sedans will probably like the Navigator's. Those expecting airy, old-school Lincoln Town Car response may not.

Bottom line, the Navigator rides comfortably and handles competently in nearly every situation. Just don't try to get racy. This vehicle is a lot of mass to move, and in quick, hard, left-right turns, all that weight wants to sway in the direction opposite of your choosing.

In 2001, Navigator was the first full-sized luxury sport-utility vehicle to hit the 300-hp barrier. Seven years later, its 5.4-liter single-overhead cam Triton V8 still generates a maximum 300 horsepower, and virtually every other big SUV has passed it by. The Triton delivers torque evenly, with similar thrust whether the engine is already turning 1,000 or 4,000 rpm, and the six-speed automatic transmission is a definite plus. There's more than enough acceleration in the Navigator to merge safely or turn quickly across traffic, and it's probably quicker than what we considered a fairly quick car in the mid-1990s. Yet at the bottom line, the Navigator accelerates more slowly than just about any luxury sport-utility we've driven in the past few years.

The automatic transmission, on the other hand, might be the best. The Navigator's six-speed comes from ZF of Germany, and it was the first of its kind in a full-size SUV. This is the same transmission used in Jaguar's flagship XJ sedan and other big luxury cars, and it's both smooth and responsive. It performs almost exactly as we like, shifting up or down when we would if we were doing it with a gear-change and clutch, and almost never shifting inappropriately. It will hold a gear when going downhill, for example, maximizing engine braking and reducing the need to use the wheel brakes.

While Navigator is down on power compared to competitors, a combination of factors, including the transmission, give it excellent towing capacity of 8,950 pounds. Moreover, its Triton V8 runs on 87-octane regular, while nearly all the other vehicles in this class demand premium fuel.

Navigator's size will appeal to some buyers, but it also brings some obvious disadvantages. It's not an easy vehicle to park (even the shorter model), and if you can parallel park this truck with any kind of consistency, you deserve some sort of award. Rear park distance control is standard, but the system offers only an electronic beep, without the graphic indicators available in some vehicles. Again, the rear back-up camera can help, but the image it displays is very small.