The GMC Yukon comes in four basic trim combinations 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 new 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 new engines should provide best in class fuel economy with even the long wheelbase, larger engine Denali XL achieving 21 mpg on the highway. The Yukon and Yukon XL models come in two basic 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 infotainment system with an 8-inch color touchscreen, rain sensing wipers, a Bose premium sound system, remote vehicle start, keyless entry and a navigation system. SLT versions include leather seating surfaces, heated and cooled front seats, heated second row seats, power folding third row seats, a heated leather steering wheel, power adjustments to the steering column and pedals and a blind spot warning system. The Yukon Denali and Denali XL come in just a single, all-encompassing trim level. The Denali comes with most of the luxury features that come with the SLT trim, however the Denali also includes a nicer sound system with active noise cancellation technology and magnetic ride control shock absorbers. The Denali also gets plenty of unique styling pieces on both the interior and exterior of the vehicle, helping to distinguish it from its less expensive sibling. Generally speaking, interior trim pieces are nicer, softer and more expensive feeling, while the exterior benefits from unique headlights, a unique grill and plenty of Denali badging. Options on the Yukon are numerous. A variety of 22 and 20-inch wheels are available, allowing buyers to customize the exterior looks of the vehicle to their taste. Interiors can also be customized and one of the more popular options on the Yukon is a very nice rear seat entertainment system that includes a Blu-ray player. Electronic systems such as adaptive cruise control or a heads up display are also available, as is a panoramic sunroof. Safety systems on the 2015 Yukon are state of the art. Electronic aids such as anti-lock brakes, traction control and stability all come standard. Optional blind spot warning can also aid on road safety. All Yukons also come with a 6-month subscription to GM's OnStar service.