The 2010 GMC Sierra 2500HD is GMC’s entry in the full-size, heavy-duty, three-quarter-ton segment, with an impressive array of features and configurations and two monster engines. Available in WT, SLE, and SLT trim levels, buyers can choose between Pure Pickup and Luxury Inspired interior themes, not to mention a full menu of cab styles and bed lengths. Standard is the two-door Regular Cab, but four-door Extended and Crew cabs, with their rear and front-hinged doors respectively, are also available. All three have the option of front bucket or 40/20/40-split bench seats, with the Extended and Crew Cabs getting a 60/40-split bench in the rear. Two bed lengths are available, with the Extended and Crew Cab having the option of a shorter 6.5-foot length in addition to the standard 8-foot bed. The base engine for the Sierra 2500 is a 6.0-liter Vortec V8 which produces 360 hp and 380 lb-ft of torque at 5,400 and 4,400 rpm, respectively. An Isuzu-developed, biodiesel-capable, turbodiesel 6.6-liter, Duramax V8 is also available. That brute of an engine produces 365 hp at 3,200 rpm and an astonishing 660 lb-ft of torque that shows up just off idle at 1,600 rpm. While both engines come with six-speed automatic transmissions with tow/haul modes, the Duramax gets the Allison 1000 six-speed, which integrates electronic engine grade braking as well. External transmission and engine oil coolers, along with a 3.73 rear axle, are all standard, although a 4.10 rear axle is available with the 6.0-liter engine. Maximum towing capacity is 13,000 pounds with an external hitch – which GM claims is best in class - but this number climbs to 15,800 pounds with the in-bed 5th-wheel hitch. There are three drivetrain configurations from which to choose, one rear-wheel-drive (RWD) and two four-wheel-drive (4WD) systems. While both 4WD systems have a low-range gear, one is a part-time system not meant to be left engaged on dry pavement, and the other is a full-time system which cares little about conditions. Both come with automatically locking center differentials and a heavy-duty suspension. While mostly unchanged from 2009, GM has added some features for 2010, including USB connectivity for the audio system with device recharge and upgraded OnStar with real-time traffic and remote start. Several luxury features like rear-obstacle detection and special power features like a power-sliding rear window and power-adjustable pedals are also available, but one of the most popular choices is sure to be the Off-Road Package with its unique suspension and full skid plates. Safety features include four-wheel antilock disk brakes with assist and anti-skid, frontal, driver, and front passenger airbags, and a tire pressure monitor. So little has changed for the Sierra 2500HD in 2010, and you can expect little change in reception. GMC does trucks well, and the 2500HD is no exception. With a list of configurations and features that allows customization between “working man’s mobile office” and “stump-puller from hell,” all you need to do is decide how much you need to haul and what you want to look like doing it.