The 2006 GMC Sierra 1500HD Classic was one of the most capable models of the GMC's 2nd-generation Sierra series. It came with a 6.0L V8 engine mated to a 4-speed automatic transmission, delivering 300 horsepower and 360 lb-ft of torque. The vehicle was offered in two trims (SLE1 and SLT) and both trims could be equipped with either Rear-Wheel Drive or Four-Wheel Drive. Notable features for the 2006 Sierra 1500HD Classic included 16-inch chrome styled steel wheels, in-dash single CD player, keyless entry, and 8-way power driver seat. Safety was addressed with four wheel anti-lock brakes, dual front airbags and power door locks. Its infotainment, although basic by today's standards, featured a radio data system and speed sensitive volume control.