Photo gallery for the 2017 GMC Sierra Denali 2500HD in dark charcoal, shot by William Maley in March 2017. Images showcase the Duramax diesel and Allison transmission badging, Denali-specific interior with IntelliLink infotainment, chrome polished alloy wheels, and exterior angles including front, rear, side profile, and three-quarter views. Read the full 2017 GMC Sierra Denali 2500HD review on Cheers & Gears.