The new QX4 is based on the popular Nissan Pathfinder, which was given a major overhaul in 1996. After spending a week behind the wheel of a dark purple QX4, I was mightily impressed with the vehicle's high quality, comfort and generous level of equipment.

But I wonder if there is $7,000 worth of difference between the QX4 and the top-of-the-line $30,000 Pathfinder LE.

Both vehicles have the same engine and transmission, nearly identical interior and much of the same equipment.

When you buy the Infiniti, you get a more advanced four-wheel drive system, a different grille and taillights and some fake (make that faux) wood trim on the dash. There are also some other minor cosmetic changes.

More importantly, you also get treated like royalty whenever you visit the Infiniti dealer for maintenance and service. That means a free loaner car and other perks.

Whether that is a strong enough inducement to pay the extra $7,000 or so is strictly a matter of personal choice.

PERFORMANCE, HANDLING

Nissan could have and should have given the QX4 a more powerful engine. Not only would that have given potential buyers a more compelling reason to choose the QX4 over the Pathfinder, but it also would have made the most luxurious version of this truck more enjoyable to drive.

As it stands, the 168-horsepower, 3.3-liter V-6 delivers adequate acceleration and nothing more. The single overhead cam motor has a lot of work to do moving the 4,300-pound vehicle. Sometimes passing slower traffic quickly strains the engine. However, in normal city driving the V-6 runs smoothly and quietly and offers good acceleration from zero to 45 mph.

TheQX4 comes only with a four-speed automatic transmission and four-wheel drive.

By simply turning a small knob on the dash, the driver can set the system totwo-wheel drive, to ''auto'' or to ''lock.''

When in the auto mode, an onboard computer constantly monitors the speed of the wheels. If it detects rear-wheel slippage, power is directed to the front wheels. If not, the QX4 bops down the highway using only the rear wheels for propulsion. In the lock position, 50 percent of the power is sent to the front wheels and 50 percent to the rear.

I drove the QX4 most of the time in the auto mode. Because it rained frequently during the weeklong road test, the roads were slippery. I could not feel the four-wheel drive system at work, either because the wheels didn't slip or because the system's delivery of power to the wheels is exceptionally smooth.

In either case, the QX4 held the road well and inspired confidence when I drove it in bad weather.