GMC's Yukon XL is the brand's flagship sport utility vehicle, and it underwent a complete redesign for 2007. Available in base SLE, SLT and top-of-the-line Denali trim levels, the Yukon XL is available with a choice of V-8 engines, some of which feature fuel management systems that deactivate four cylinders during low-load situations. According to the company, this technology can improve fuel economy by about 10 percent. Competitors include the Ford Expedition EL, Nissan Armada and Toyota Sequoia.
Topping the range of available engines is a 6.2-liter V-8 that does without the fuel management system but boasts 380 horsepower. Rear-wheel drive is standard across most models, but four-wheel drive is available.
For 2008, side curtain airbags are standard across the Yukon XL lineup, and a new rear-wheel-drive Yukon XL Denali joins the all-wheel-drive model. Specific changes to the heavy-duty 2500 series include a newly standard electronic stability system and six-speed automatic transmission. The Yukon XL is closely related to the Chevrolet Suburban, which underwent a similar redesign for 2007.
The Yukon XL sports sleeker styling and better-integrated lower body panels than the prior generation. Larger headlamps and a cleaner front help distinguish the current Yukon XL from its predecessor. Fenders, fog lights and lower side cladding are integrated into the body to create a more continuous appearance than the previous Yukon XL's pieced-together look.
Seventeen-inch wheels are standard on most trims, but the 2500 gets 16-inch rims. The Yukon Denali upgrades to 18-inch wheels while also adding unique headlamps, grille and taillamps. Twenty-inch wheels are optional for all trims. Denali editions include a standard power liftgate. Optional parking-assistance features include a rearview camera and sonar rear parking sensors. Power-operated, retractable running boards are available.
A lower dashboard with a traditional instrument panel hump replaces the boxy dash from previous Yukon XLs. Higher-quality fixtures include flush-mounted controls, low-gloss materials and chrome instrument surrounds. Three rows of seats can accommodate up to nine occupants if configured properly, and front-seat occupants will find three inches of additional hiproom compared to the previous generation. Second-row passengers lose more than an inch of headroom, and third-row passengers sacrifice headroom and legroom.
Cargo volume measures 45.8 cubic feet behind the third row. With the third row removed and the second row folded — made easier with an available power-folding feature — cargo volume increases to 137.4 cubic feet.
Manual tri-zone climate control is standard in SLE trims. SLT and Denali editions get automatic climate control and leather seats. Denali versions up the luxury ante with heated first- and second-row seats, a premium audio system, rain-sensing windshield wipers and an available heated steering wheel.
Under the Hood
The Yukon XL can be powered by a choice of V-8 engines. A 5.3-liter V-8 propels regular-duty Yukon XLs; in rear-wheel-drive models the engine has an iron block, whereas four-wheel-drive versions have an all-aluminum mill. Both engines — which can run on either regular gasoline or E85 ethanol-based fuel — feature a fuel management system that can deactivate four of the eight cylinders when power needs are low. Total output for rear-wheel-drive models is 320 hp and 340 pounds-feet of torque, while four-wheel-drive versions make 310 hp and 335 pounds-feet of torque.
An optional 6.0-liter V-8 features variable-valve timing and cylinder deactivation and develops 366 hp and 380 pounds-feet of torque. Heavy-duty 2500 series versions receive an iron-block edition of the 6.0-liter V-8 that has variable-valve timing but lacks the cylinder deactivation. This engine is rated at 352 hp and 383 pounds-feet of torque. All 5.3-liter and 6.0-liter V-8s team with a four-speed automatic transmission, except on the Yukon XL 2500. Its 6.0-liter V-8 drives a six-speed automatic transmission for 2008. When properly equipped, the Yukon XL 1500 can tow up to 8,100 pounds.
The horsepower leader is the 6.2-liter V-8. It utilizes variable-valve timing but lacks cylinder deactivation; it develops 380 hp and 417 pounds-feet of torque. This motor is available only in the Yukon XL Denali, where it drives a six-speed automatic.
Standard safety equipment includes four-wheel-disc antilock brakes, traction control and an electronic stability system with rollover mitigation technology. GM says the system senses when the vehicle is likely to tip, then triggers the stability system in an attempt to prevent it. (To date, only Ford Motor Company's Roll Stability Control feature can sense that a rollover has begun and attempt to forestall it.) Standard side curtain airbags cover all three rows of seats. The front seat belts feature pretensioners that can activate in the event of a rear-end collision.