The AT4 comes standard with a 5.3-liter V8, which is rated for 355 horsepower and 385 pound-feet of torque. Buyers can upgrade to a 6.2-liter V8 with 420 hp and 460 lb-ft.
Other tweaks for the Sierra AT4 include dark-finish exterior trim, a body-color grille and bumper, vertical-oriented red recovery hooks, "Kalahari" seat inserts and rubber floor mats.
An 8-inch touchscreen infotainment system features Apple CarPlay and Android Auto. My test vehicle also features wireless phone charging and built-in navigation.
