The 2015 GMC Sierra 3500HD, belonging to the third-gen GMC HD trucks, is a powerful and sturdy pickup truck known for superior towing abilities and comfortable ride quality. It's offered in four trims: Base, SLE, SLT and the plush Denali, with rear-wheel or four-wheel drive configurations. Engine options include a 360-hp 6.0L V8 and a 397-hp 6.6L turbodiesel V8; paired with either a 6-speed automatic or 6-speed Allison 1000 transmission respectively. Standard technology boasts of a 4.2-inch display with GMC's IntelliLink info system, while upper trims enjoy an 8’’ touchscreen, Bluetooth, and OnStar with 4G LTE and built-in Wi-Fi. Safety features include stability control, 4-wheel ABS, front, and side airbags, and optional driver aids like rearview camera and parking sensors.