The Yukon XL is a great choice for towing cars, boats, horses, and travel trailers.A Yukon XL 1500 is rated to tow up to 8200 pounds, while the heavy-duty 2500 version can tow up to 9700 pounds.With its long wheelbase and heavy-duty construction, the Yukon XL is a highly stable platform for towing while offering the interior cargo advantages of a full-size SUV.The standard 5.3-liter V8 offers excellent horsepower and torque, and a 6.0-liter V8 is available for more towing power.

The Yukon XL seats six to nine people, depending on the seating configuration.There are many vehicles that seat seven people without taking up so much space to do it, but few quite so comfortably, nor with so much room left over for cargo.

The optional leather seats are wonderfully comfortable for long distances.The driver sits way up high and feels like he or she is master or mistress of his or her domain.The pedals adjust for long or short legs.The instruments and gauges are stylish.Interior small items storage is intelligently designed and all over, including a huge center console.

Those in the second row will find a lot of leg room.Bucket seats with a center console between them are available for the second row, turning them into first-class accommodations; and there is an optional power folding option, making it easier for third-row passengers to climb in.There's even decent legroom and good headroom in the third row, something few SUVs can claim.

At the top of the line is the Yukon XL Denali.The Denali is almost a separate breed.It has its own engine, a 6.2-liter V8 rated at 380 horsepower and 417 pound-feet of torque.The Denali also offers a more sophisticated all-wheel-drive system.The Denali comes standard with the AutoRide active electronic suspension, which is optional on the regular Yukon XL.

A liftgate is available that raises and lowers under power, a Bose sound system, a navigation system, and a DVD rear-seat entertainment system are available, in addition to a rearview monitor that improves safety and makes it easier to hook up trailers.

The Yukon XL was completely redesigned for 2007.The 2008 Yukon XL models come standard with curtain side airbags.Yukon XL 2500-series models get a six-speed automatic for 2008, and a new 2WD version of the Yukon XL Denali is available.

The 2500-series models have truck tires and a heavier suspension using leaf springs.The SLE 2WD 2500 ($39,585), SLE 4WD 2500 ($42,385) and the SLT 2WD 2500 ($40,380) and 4WD SLT 2500 ($43,180) come with a 352-hp version of the 6.0-liter V8 that makes 383 pound-feet of torque.Also, 2500 models get a six-speed automatic for 2008.

Also offered are the luxurious 2WD Denali ($48,130) and AWD Denali ($51,175).The Denali's all-wheel-drive system lacks low-range gearing.The Denali models come with a 6.2-liter V8 that produces 380 horsepower and 417 pound-feet of torque along with a six-speed automatic transmission with manual mode and GMC's AutoRide active electronic suspension.

They all have a Tow/Haul mode, which reduces upshifting and downshifting, and also shifts quicker, so the transmission doesn't work so hard when pulling a big load.Transmission oil temperature is part of the instrumentation (along with a tire-pressure monitor).

The SLE standard equipment includes cruise control; three-zone manual climate control; AM/FM/CD/MP3, eight-speaker stereo with XM satellite radio; OnStar assistance with one year subscription; driver information center; the usual powered features, with the outside mirrors heated and foldable; a six-way power driver's seat; leather-wrapped, tilt steering wheel with audio controls; cloth upholstery; auto-dimming rearview mirror; 40/20/40 split front bench seat; six-way power driver's seat; 60/40 split folding second-row bench seat; two-passenger third-row split folding seat; automatic headlights; roof rails; side steps; locking rear differential; three power outlets; and P265/70R17 all-season tires on bright aluminum wheels.Also standard is a tow package with a heavy hitch, seven-pin wiring harness, two-inch receiver and electric brake control harness.A 3SB package for SLE ($835) adds front bucket seats, a power front passenger seat, a front center console, rear radio and climate controls, and fog lights.A Convenience Package ($560) has rear park assist, power-adjustable pedals and remote engine starting.

SLT models get tri-zone automatic climate control with rear controls, front tow hooks, leather upholstery, front bucket seats with six-way power adjustment, front center console, six-disc CD changer, rear seat audio controls and outputs, universal garage door opener, fog lights, remote engine starting, power adjustable pedals, rear park assist, and polished alloy wheels.A 4SB option package for SLT ($3,705) adds heated, 12-way adjustable front seats with lumbar adjustment; memory for the driver's seat and mirrors; Bose nine-speaker audio system with subwoofer; roof rack; and power-folding exterior mirrors with integrated turn signals, driver's side auto-dimming, and reverse tilting.

Denali models come fully loaded, with a wood and leather-wrapped steering wheel; second-row bucket seats; heated first- and second-row seats; 12-way adjustable front seats with lumbar adjustment; memory for the driver's seat and mirrors; power-folding second-row seats; removable three-passenger split-folding third-row seat; power-folding exterior mirrors with int.

The Suburban and Yukon XL are familiar vehicles on the road.They share styling but differ in some details.For example, the Yukon XL has a cleaner air intake below the bumper than the Suburban, a different shape for the headlights, and the grille is not split.

While very large in size, the Yukon XL looks smooth, if not sleek.The contours are gently shaped.It isn't edgy like the Cadillac Escalade is.There's not a lot of flashy chrome and the side moldings and door handles are body colored.

The running boards are integrated and unobtrusive, extending no farther than necessary, with a black grippy coating.The tinted glass behind the C-pillar is expansive, and looks nice.The front end has a clean appearance, with beefy block-like headlamps over a front bumper fascia.All the panel tolerances are a tight fit.It's nice to see that GM can produce this kind of quality.

The rear window opens separately, which is convenient.Our SLT had the optional power liftgate, and we're not sure what we would have done without it.The liftgate is aluminum, however, which makes opening and closing it manually a bit easier.

The instrument panel and center stack are elegant and worthy of a higher-end vehicle.The Denali model is richer still, with a wood and leather-wrapped steering wheel and darker wood trim than the other models.

We found the touch-screen radio/navigation system easy to use, much easier to operate than in so many cars, Mercedes, for example.We set the radio stations we liked and could quickly switch from favorite XM to AM to FM stations with the push of a single button; many vehicles require switching bands, then switching stations.This ease of operation makes daily driving more enjoyable.

The switchgear is simple, and the instrumentation is clean.The console is huge, with a deep storage box and a tray on top.The glovebox is large.Two cupholders are provided in a removable tray forward of the console and they work very well.There's another cupholder in each door pocket.A slot in the dash just left of the turn signal is perfect for coins or toll-road tickets.The pedals are adjustable, to accommodate short and tall drivers with the press of a button.

The rearview camera is useful and improves safety, so we strongly recommend this option.Shift into Reverse and an image of what's behind you appears on the navigation screen.This makes parallel parking much faster and much easier, and it helps when maneuvering in parking structures and other tight locations.The camera works well at night, benefiting from the reverse lights: One night we had to back up a narrow winding driveway squeezed by trees, and it could only be done by using the monitor.It was tricky.The backup lights did a great job of lighting the road for the camera; looking over our shoulder, our naked eye couldn't see the road nearly as well.Most important, the backup camera can help the driver spot a small child or an adult behind the vehicle, possibly averting a tragedy.The system also makes hitching a trailer much easier, allowing the driver to precisely position the ball under the trailer hitch on the first attempt, which beats jumping out of the vehicle multiple times using the traditional trial-and-error method.

The Yukon XL can seat six, seven, eight or nine passengers, depending on the seats selected.Our SLT had the second-row bucket seats, with room for seven, in a two/two/three configuration.

The second row offers good leg room, at least with the two bucket seats: 39.4 inches, nearly as much as in the front.Second-row passengers have their own console, with an elbow tray and two cupholders each.They have their own audio controls too, and a front-row seat for the DVD screen that drops down from the headliner, and uses wireless headphones.The second-row bucket seats come with a console between them.

An optional power feature allows folding the second-row seats with the touch of a button on the instrument panel or C-pillar.It's slick: the seatbacks fold flat against the lower cushions, and then the seats flip up against the backs of the front seats.

Depending on the package, the third row seats two or three.Split 60/40, these seats fold and tumble, but don't fold flat into the floor like some competitors.The third-row seats flip up against the back of the second row.This fold-and-tumble feature sacrifices some quick cargo space because the seats don't fold flat, though there's still a lot of room compared to other SUVs.

Head room in the third row is good, and leg room is okay (34.9 inches).There is a great view through the wraparound glass, so it doesn't feel cramped or claustrophobic back there.But with the optional center seat, all you'll ever fit in the third.

GM's trusty 5.3-liter Vortec V8 is the standard choice and it's a good one, making 310 horsepower and 335 pound-feet of torque with 4WD and 320 hp and 340 pound-feet of torque with 2WD.GM's Vortec is one of the best V8s around, though Chrysler's 5.7-liter Hemi V8 and Toyota's new 5.7-liter V8 are also quite impressive.When you floor it, it actually feels like it has more horsepower than advertised, considering the weight of our test vehicle was 5758 pounds.

There's a smooth four-speed automatic transmission to go with it, and with all that torque, a fifth speed in the transmission might not be needed, though the big Japanese V8 SUVs all have five- or six-speed automatic transmissions.In the Yukon XL, the 5.3-liter V8 is FlexFuel capable, meaning the engine can run on either unleaded regular fuel or E85 (85 percent ethanol and 15 percent gasoline).

If you need more power for towing, get the optional 366-hp 6.0-liter V8, which boasts 380 pound-feet of torque, handy for getting up Southern California's Grapevine and other steep grades.

If you have a seriously heavy trailer you can choose one of the 2500 series models, which have a 352-hp 6.0-liter V8 with 383 pound-feet of torque.

You can also opt for the Denali XL, with its Corvette-based 6.2-liter engine making 380 hp and 417 pound-feet of stump-pulling twist.

Active Fuel Management is standard on the 5.3-liter V8 and the 6.0-liter V8 in 1500 models.AFM shuts down four of the eight cylinders when they're not needed to save fuel.But there's one big catch: all the cylinders are needed virtually all time, unless you're totally off the throttle, in which case they all basically shut down anyhow.So the amount of fuel saved is questionable.

Fuel economy with the 5.3 V8 and 2WD is an EPA City/Highway-rated 14/20 miles per gallon.We drove nearly 300 miles in a 2WD Yukon XL in an even split between around town and running 75 mph on the freeway, and averaged 15.8 mpg.With the 6.0-liter V8, the EPA ratings are lower at 12/17 City/Highway.(Better is the Yukon Hybrid's 21/22 mpg.)

Ride quality in the Yukon XL is excellent, overall.Even when the optional 20-inch wheels are chosen, the suspension deals deftly with road imperfections and potholes.We prefer taller tires on our trucks, however.The Yukon XL is very stable, though it wallows a bit on undulating freeways.

The rack-and-pinion steering feels fairly direct, though as in other big SUVs it is a bit slow.Also like all large SUVs, the Yukon XL is prone to body lean in turns and doesn't respond well to quick changes of direction.It's a full-size truck and needs to be driven accordingly and with respect for others, not like it's a sports car.

AutoRide, the optional self-leveling suspension, is a high-tech, active suspension, meaning it electronically adjusts to the road, as read by sensors.It reduces some of that body lean in corners, as well as nose dive under hard braking.

Hard winds can blow it around.Driving in an 25-mph crosswind on the freeway at 75 miles per hour, our Yukon XL swayed all over the road, because of its billboard-like profile.So if you're pulling a 20-foot enclosed trailer, you'll want to slow down in heavy wind.

The brakes feature big vented rotors, 13 inches up front and 13.5 inches in the rear.This adds up to security and safety when you're trying to get stopped with a boat or trailer pushing you from behind.The brakes on these GM trucks are far better than they were a decade or so ago if you have memory of those.

Sam Moses filed this report to NewCarTestDrive.com from the Pacific Northwest's Columbia River Valley.Correspondent Kirk Bell contributed from Chicago.