The GMC Yukon XL is an enlarged version of the GMC Yukon. The Yukon XL is completely redesigned for 2021, trying to be more appealing than its predecessor. With its long wheelbase, it has more third-row legroom, and more cargo space, offering more passenger comfort and more room for your gear. A new off-roading AT4 trim joins the SLE, SLT and Denali trims. All Yukon engines are now paired with a 10-speed automatic transmission and later in the model year, a diesel powertrain will add to the two V8 options.