Driven: 2020 GMC Sierra 1500 AT4

We spent some time in Wyoming putting GMC’s 2020 trucks through their paces, including the Sierra 1500 AT4 on a dirt and rock course. It has a 2” lift, a 2-speed transfer case, Rancho monotube shocks, skid plates, a locking rear diff, and is now available with a 3.0L Duramax turbo diesel, making 277 hp and 460 lb-ft. of torque.