Power for the 2007 GMC Yukon XL comes from one of two eight-cylinder engines. The entry-level motor is a 5.3-liter small block V8 with 320 horsepower at 5,300 rpm and 340 lb.-ft. of torque at 4,200 rpm. A four-speed automatic transmission is standard. Next up is a 6.0-liter V8 offering 355 horsepower at 5,400 rpm and cranking out 365 lb.-ft. of torque at 4,400 rpm through a six-speed automatic transmission. Both engines feature Active Fuel Management, the new name for what most know as displacement-on-demand, a system that deactivates four of the engine’s eight cylinders when less power is needed. GMC representatives claim that this technology allows the new Yukon XL to achieve fuel economy in the low 20s on the highway at 60 mph. Also noteworthy is the flex-fuel status of these engines. Either can operate on 87-octane gas, ethanol, or a mix of both.

The 2007 GMC Yukon XL Denali model gets its own engine, a 6.2-liter V8 with 380 horsepower at 5,700 rpm and 415 lb.-ft. of torque at 4,400 rpm controlled by a six-speed automatic. Active Fuel Management and flex-fuel capability are not features of this powertrain.