The GMC Yukon comes in four basic configurations: Yukon, Yukon XL, Yukon Denali and Yukon Denali XL. XL versions of the Yukon come with a longer wheelbase and more interior room, while Denali versions are packed full of luxury. Two engines power the Yukon: A 5.3L V8 with 355 horsepower supplies power to Yukon and Yukon XL models, while a 6.2L V8 with 420 horsepower provides thrust for Denali and Denali XL versions. GMC claims that the engines should provide best-in-class fuel economy. Within the Yukon and Yukon XL models are three trims -- SLE and SLT. SLE versions are more basic but still include plenty of amenities. Highlights on the SLE include a rear vision camera, front and rear park assist, an IntelliLink infotainment system with Apple Car Play and 10.2-inch touchscreen, rain-sensing wipers, remote vehicle start, and keyless entry. SLT versions include leather seating surfaces, heated and cooled front seats, a hands-free liftgate and a blind-spot warning system. At the top of the lineup, the Denali comes with all the luxury features from the SLT trim, but with an upgraded sound system, magnetic ride control shock absorbers, a heated steering wheel, heated second-row seats, power-folding third row seats, and a navigation system. The Denali also gets unique styling both inside and out. For 2021 a new AT4 trim was added to the 4x4 Yukon standard equipment includes skid plates, two tow hooks, automatic ride control, and auto dimming mirrors with turn signal indicators. Safety systems on the 2021 Yukon are state of the art. Electronic aids such as anti-lock brakes, traction control and stability all come standard. Safety features across the lineup include front and rear parking sensors, forward collision mitigation, and pedestrian detection while all trims aside from the SLE trim also come standard with active lane departure, blind spot warning and rear collision mitigation.