Ford's SUV revamp has explorer blazing new trails.

The ground-up redesign of the Ford Explorer ranks as one of the most important events of the 2006 model year.

It has been the category sales leader for 15 consecutive years and has already put about 5.5 million vehicles in the driveways of American consumers.

There were few vehicles that I d have tested in the past 20 years that made more of an impression than the original Ford Explorer in 1990. First off, it was manufactured by Ford's truck division, which had the reputation--then as now--of building the best vehicles made in the United States, so there was the perception that quality was baked in, not added on.

I distinctly remember thinking at the time that the Explorer was so well built it could have come from BMW.

Secondly, the size seemed just right for the typical suburban family. And finally, the performance, particularly ride and handling, was excellent for that era. But while the original Explorer gave Ford a huge edge in the marketplace, many new competitors have caught up or even surpassed Ford's cash cow.

But there is a very important question that lurks like the 600-pound gorilla. What's to become of the sport utility vehicle segment in general--particularly the heavy fuel slurping, truck-based vehicles like the Explorer? Will consumers continue to buy these vehicles by the millions, or will they retreat to car-based SUV crossovers such as the Ford Freestyle and the Nissan Murano or even go to station wagons and minivans that consume less gasoline?

The traditional SUV came to market able to do several things well: tow a boat or trailer and do serious off-roading while transporting a family and its gear. The redesign of the Explorer is aimed to make it the best conventional SUV on the market through a significant number of advances in structure and technology.

The classic SUV is based on a truck chassis, which means that it rides on a big steel frame with the body bolded on top. In auto lingo, this is referred to as body-on-frame construction, as opposed to the unibody architecture used in cars and crossover SUVs.

For the redesign of the Explorer, Ford has gone all out to make this structure as stout as possible with a fully boxed frame, which means that in cross section the frame rails look like a circle that has been flattened on all four sides. Tipped on end, the frame of the Explorer resembles a ladder--massive side rails crisscrossed with stout lateral beams. This structure provides massive resistance to both bending and twisting forces.

The 2006 Explorer records an eye-popping 63 percent increase in bending resistance and a 55 percent resistance to twisting forces.

Another major step forward in the design of the 2006 Explorer is an independent rear suspension, which means that a bump affecting one rear wheel will not excite the other rear wheel. This setup improves ride and handling as well as better space utilization within the cabin.

The net result of the strong body, improved suspension and advanced methods of mounting the body on the frame is an amazingly quiet ride. At fast cruising speeds, noise and vibration are reduced to luxury sedan levels. The only noise noticeable at 80 mph was a bit of a hum from the aggressive all-terrain tires.

The Explorer's vehicle dynamics under extreme conditions benefit from new technology. Thanks to AdvanceTrac, Ford's new all-wheel-drive system, rollovers and loss-of-vehicle control should be significantly reduced. The system incorporates the anti-lock brake system, traction control, yaw control and a vehicle-roll motion sensor. I had the opportunity to put the new Explorer through its paces on a very tight slalom course, where, despite its size and weight, it proved to be very stable and controllable.

The V-8 engine in our test Explorer has also had a makeover, resulting in much more power and better fuel economy. Mated to a very responsive six-speed automatic transmission, the Explorer--while no speed burner--can easily pass slower moving traffic. And of equal importance, the new engine is exceptionally quiet and refined in all modes of operation.

Here's my bottom-line assessment. If the potential owner is really going to tow a sizable boat (say 5,000 to 7,000 pounds) or really bash around off-road, then the architecture and mechanical sophistication of the Explorer make sense. There's nothing that can do a better job at the price.

But if the SUV's primary purpose is a people transport, the new Explorer is overkill, and a crossover SUV would better serve the potential buyer. Hey, even though the new V-8 gets significantly better gas mileage than its predecessor, EPA mileage of 14/city and 20/highway is a lot of expended energy.

Cordell Koland is an automotive journalist based in California (1)s central coast. He can be reached at [e-mail].

Ford Explorer

Price as tested: $36,555.

Engine:

Type: 4.6-liter V-8.

Horsepower: 292 @ 5,750 rpm.

Torque: 300 foot-pounds @ 3,950 rpm.

Fuel economy, automatic transmission:

City: 14 mpg.

Highway: 20 mpg.

Curb weight: 4,777 pounds.