With a 14-inch increase in wheelbase and a 20-inch increase in overall length, the Yukon XL adds almost 30 cubic feet to the cargo volume of the Yukon. Available in half-ton (1500) and three-quarter-ton (2500) versions, the XL can tow up to 8,100 or an impressive 9,600 pounds, respectively. Each version is available in four trim levels.

New for 2009 is a standard 6-speed automatic transmission, replacing the 4-speed offered in previous years. Also, heavy-duty towing options and an integrated brake controller account for the XL's beefy towing capacity. A blind-zone alert system, integrated rearview camera system, rear parking assist, and automatic wipers are all new for 2009, as well as Dark Crimson Metallic paint. The 3/4 ton trims feature a heavier-duty multi-leaf rear suspension and a hydraulic brake booster to handle their extra towing capacity.

Available in both rear-wheel-drive and four-wheel-drive trims, the Yukon XL earns 14/20 and 14/19 mpg ratings from its 320-hp, 5.3-liter Vortec V8. This is not unimpressive, especially considering its nine-person seating, huge towing capacity, and optional flex fuel capability. (A standard, non-flex-fuel 5.3-liter is also available.) Additional engine options for the XL are a 366-hp, 6.0-liter V8 for the 1500 and a 352-hp, 6.0-liter V8 for the 2500, all with GM's Active Fuel Management cylinder deactivation, which shuts off four cylinders during low load times to conserve fuel.

Specific for the XL are integrated running boards with an available power option, 16- or 17-inch wheels, an optional powered liftgate, and standard powered and heated side mirrors. Standard front and head-curtain airbags come with all four trim packages, as well as a tire-pressure monitoring system and one year of OnStar, with the level dependent on trim package.