The GMC Sierra 1500 – when taken in combination with its Chevrolet Silverado 1500 twin – is one of the most popular vehicles in the United States. The Denali used to be the top dog in Sierra trim levels, but in recent years, it’s been overshadowed by the AT4X and the Denali Ultimate. The Sierra 1500 Denali is available only in the Crew Cab bodystyle, either with a short or a standard cargo box, and in rear-drive or four-wheel drive. Three different engines are available, from the 5.3-liter V-8, the 3.0-liter Duramax inline six-cylinder diesel, or the 6.2-liter EcoTec V-8 (in four-wheel drive only). All of the trucks feature a 10-speed automatic transmission.