A 6.0-liter, Vortec V8 engine powers the rugged Sierra 2500HD, while a 6.6-liter Duramax diesel engine is optional. Like all Sierras, the 2500HD is available in a wide array of bed sizes, wheelbases, drive types and cab sizes, as well as a variety of trim levels. Safety features include driver and passenger front air bags, tire pressure monitoring system and four-wheel anti-lock disc brakes. Stability control is optional on some models. The Sierra 2500HD is visually unchanged from 2008, but adds the availability of Bluetooth, XM NavTraffic and a rearview camera.