When it comes to full-size SUVs, they don't get much bigger than the Yukon XL and its Denali XL stablemate. Coming in at over 18 feet long and weighing almost three tons, this behemoth comes in half-ton and three-quarter-ton models. An imposing sight when viewed from the rearview mirror of your average family sedan, its expansive dimensions do more than inspire fear in the hearts of fellow drivers. The Yukon XL boasts seating capacity for nine and the ability to tow a 10,000 lb. trailer when properly equipped, making it one of the most versatile sport-utes available. Accomplishing such heroic feats of hauling requires serious muscle under the hood and the XL has the goods. Half-ton models get a 5.3-liter V8 rated at 285 horsepower and 325 ft-lbs. of torque, while three-quarter-ton models get a choice of either a revised version of last year's 6.0-liter, now rated at 320 hp, or an all-new 8.1-liter brute that delivers 340 hp and 455 ft-lbs. of torque. GMC points out that even the smaller 6.0-liter engine boasts more power than the V10 available in the Ford Excursion, while the 8.1-liter engine enjoys a solid 30 point lead in both the horsepower and torque race.

All half-ton Yukon XL models utilize an independent torsion bar front suspension and a five-link coil-spring rear setup that delivers a satisfying ride whether you're on the highway or off the beaten path. Three-quarter-ton models utilize the same torsion bar setup up front, but rely on two-stage Smooth Ride leaf springs in the rear that provide a comfortable ride while retaining the capacity for heavier loads. An optional trailering package adds even higher rate springs and retuned shocks for better handling of extreme loads.

Yukon XL buyers can choose between two different trim levels: base SLE or uplevel SLT. SLEs come standard with front and rear air conditioning, aluminum alloy wheels, and deep tinted glass. Add to that power windows, locks and doors, a nine-speaker AM/FM CD stereo, and an electrochromic rearview mirror with an integrated compass and it's easy to see why these make great family vehicles. Step up to SLT trim and you'll enjoy leather upholstery, heated driver and passenger front seats with power lumbar and lateral support, electronic climate control, and the OnStar communications system. Front and side airbags are standard, and an optional traction control system keeps 2WD XLs on the road when the going gets slippery.

Although hardly groundbreaking on the outside, the Denali XL features a monochromatic paint scheme and an exclusive polished metal grille that gives it a distinctive, yet understated look. On the inside, the Denali offers optional second row captain's chairs (reducing capacity to seven). There's a long list of standard features that includes: leather-covered seats, steering wheel and grab handles; a 250-watt 11-speaker Bose stereo system with an in-dash six-disc changer; six-way power driver and passenger seats with dual-zone heating; rear seat audio controls and cupholders; and a multifunction trip computer. The next-generation OnStar communications system is an available option providing not only navigational assistance and concierge services, but also hands-free personal calling and a Virtual Advisor that allows access to Web-based information such as e-mail and stock quotes.

Although the Denali XL coddles its passengers with a luxurious interior, it still packs plenty of high-performance. The standard engine is a 6.0-liter V8 rated at 320 horsepower and 365 ft-lbs. of torque, a step above the Lincoln Navigator's 300 hp V8. As if a class-leading engine and versatile transmission aren't enough, the Denali XL adds the performance and safety of full-time all-wheel drive.

When it comes to providing plenty of room for a large group of passengers, it's hard to beat the Yukon XL or Yukon Denali XL. Although we would like to see higher quality interior pieces and an overall improved level of fit-and-finish, we still love the big sport-ute. The wide-range of engines and high level of standard equipment make it a nice place to spend time on long trips with the family. Even if you're not saddled down with restless rugrats, the Yukon XL will still prove useful with its huge cargo capacity and ability to haul a sizeable trailer with ease.