GMC ≫ YukonGMC Yukon AT4 (2021, fifth generation) photosby Joshua ThompsonThe 2021 GMC Yukon AT4 is a new trim line with more offroad ability including adaptive air suspension, 2-speed transfer case, and 20″ all terrain tires. ◄ PrevNext ►Credit: GMC (L to R) 2021 GMC Yukon Denali and AT4 Tags:at4fifth generationgmcyukon