The 2010 GMC Sierra differs only slightly from its Chevrolet Sierra sibling. The combination of engines, transmissions, cabin configurations, box lengths and chassis ratings can be daunting. The 1500 uses a 195 hp 4.3L V6, 302 hp 4.8L V8, 315 hp 5.3L V8 and 403 hp 6.2L engines, with four- or six-speed automatics depending on trim. The 2500 uses a 360 hp 6.0L V8, and can be optioned with GMC’s excellent 6.6-litre turbodiesel V8 that produces an astonishing 660-lb-ft of torque. The 3500 gets different suspension and a dually option too. Interior is either work-truck basic or leather-lined luxury, especially in Denali 1500. Sierra Hybrid uses the same technology as the Yukon Hybrid, meaning a 332-hp 6.0-litre V8 with a full battery pack that can shut off the engine at stoplights, and travel short distances on electric power alone.