Immediately apparent is the fact that the whole dashboard is carryover. It's the same chunky, plasticky place to be that, while likely highly functional, did little to impress when unveiled at the Detroit Auto Show. Really, only the volume, tuning and climate control knobs look different from those in the Silverado. They appear to have a different ridged pattern on the edges, and are possibly a shinier, glossier finish. The steering wheel also looks different, with a chunkier center and more svelte spokes.
The Sierra exterior would seem to be better differentiated. The headlights are very different in that they wrap around the fenders more so than on the Chevy. The grille looks more vertical and aggressive than the Silverado's. The wheel arches also differ in that the forward corners are rounded and the rears are more squared off.
The GMC Sierra will be revealed March 1 in Detroit. As per usual, it will probably share all of its powertrain bits with the Silverado. That means at least 5.3- and 6.2-liter gasoline V8s and the new turbocharged 3.0-liter inline-six diesel engine.