Under the hood, the pickups feature three new EcoTec3 truck engines ? a 4.6-liter V-6, 5.3-liter V-8 and 6.2-liter V-8 ? each matched with six-speed automatic transmissions. They each include direct injection, cylinder deactivation and continuously variable valve timing aimed at improving performance and efficiency. Lightweight aluminum blocks cut weight, GM said.
GM describes its new 4.3-liter V-6 for the budget-conscious, while providing "ample torque to power a crew cab and tow a trailer"; its 5.3-liter V-8 as having more horsepower and torque and improved fuel economy; and a 6.2-liter V-8 "expected to be the most capable engine."
The new trucks will feature "cruise-grade braking," or downshifting when going downhill to reduce brake wear. They also have electronic power steering.
The 2014 extended-cabs have new front-hinged rear doors with exterior handles, allowing back seat passengers to exit the truck while front doors remain closed. Both trucks in crew cabs will offer customers a second length option, a longer 6-foot, 6-inch box for carrying more cargo.
Several safety features also are available as options, including alerts for forward collisions and lane departure, and a driver alert seat, which vibrates to alert the driver of roadway dangers.
The Sierra will offer an All Terrain model, which has a special exterior.
Inside the trucks, buyers will find new instrument clusters with six gauges and driver information centers, with many features that can be voice-controlled. The interiors also will have an available 110-volt outlet, USB ports and 12-volt outlets.