It's not often a three-quarter-ton SUV can be wheeled into a parking spot like a family sedan, but the availability of four-wheel steering on General Motors' big SUVs has dramatically enhanced the maneuverability of GMC's Yukon XL 2500 and the Chevrolet Suburban 2500.

This system, a $4,495 option, was offered on last year's GMC Denali pickup. When activated by a button on the instrument panel, it turns the rear wheels in the opposite direction as the front wheels at low speed and in the same direction as the fronts at high speed. Four-wheel steering transforms a normally cumbersome vehicle into one that drives as if it were much smaller, plus it improves stability in crosswinds and lane-change maneuvers. Four-wheel steering also improves trailer towing. GMC says that the truck and trailer "move as if they were one." Turning all four wheels reduces the Yukon XL's turning radius from 44 feet to 35 feet, which is pretty remarkable for a vehicle with a 130-inch wheelbase. Turning into parking spaces no longer takes two tries, and parallel parking is a snap.

The three-quarter-ton's 6.0-liter Vortec V-8 and heavy duty chassis make it an ideal tow vehicle, and that is how the test vehicle was configured. The four-wheel-drive model can tow 5,443 pounds, while two-wheel-drive can tow 12,000 pounds. When towing a trailer, the outside mirrors can be extended electronically for better rear vision. The right side mirror is not convex like most mirrors, and that means there is a sizable blind spot on the right side. The 320-horsepower, 6.0-liter Vortec V-8 is an absolute gem, and its low-speed power makes it especially good for towing. Even though it lacks multiple valves and overhead cams, this engine is strong and smooth. The electronic throttle control was hypersensitive, and the vehicle surged as my foot moved when the vehicle rode over bumps. Gas mileage figures are not required for vehicles over 8,500 pounds, but suffice it to say that this vehicle has quite an appetite for fuel. The test vehicle's four-wheel-drive system can be operated in two-wheel, four-wheel or four-wheel automatic modes. Low range is available for off-road conditions.

The automatic transmission has a tow-haul setting that changes the transmission's shift points for optimum response when climbing hills or pulling a trailer.

The Yukon XL is designed to haul up to seven passengers in three rows of seats. The test vehicle had second-row captain's chairs. The folding third-row seat would be more useful for carrying large objects if it folded flat into the load floor.

Comfort and convenience are given top billing. A three-zone heating/cooling system enables passengers to pick their own temperature. Various audio and video systems keep back-seat riders occupied. The rear-seat entertainment center, a $1,295 option, includes a DVD player with a screen that flips down from the ceiling. The test vehicle was also equipped with an XM satellite radio receiver. XM radios receive signals for 100 coast-to-coast channels, including 71 for varying types of music, that stay the same all across the country. XMÕs sound is top-notch and the choice of programming vast. A $9.99 monthly subscription fee is required.

GMC cleaned up the design of the instrument panel which now contains readouts for as many as 30 vehicle functions. The audio system and center console have been simplified.

The base price of the test truck was $41,262. The option list amounted to an additional $13,395, and it consisted of leather seats, Bose stereo, rear-seat audio controls, power adjustable pedals, cargo net, in-dash six-disc CD player, XM radio, DVD player, quadrasteer, second-row captain's chairs, heavy duty trailer package, roof-marker lights, 4.10 rear axle ratio and side airbags.

The sticker price was $55,447.

Three years or 36,000 miles.

Point: Four-wheel steering was the hot ticket on some cars in the early 199 s, but it fell out of favor. GMC now offers it on the Yukon XL 2500, and it is brilliant because it enhances maneuverability and stability, especially for towing.

Counterpoint: An overly sensitive throttle pedal was annoying, and carrying cargo was not easy unless the third seat was removed. Expect to spend a lot on gasoline.

Engine: 6.0-liter, 320-hp V-8
Transmission: automatic Four-wheel drive
Wheelbase: 130 inches
Curb weight: 5,760 lbs.
Base price: $41,262
As driven: $55,447
Mpg rating: not avail.