The HD Silverado and its twin the GMC Sierra HD are designed
for heavy towing and hauling. The 6.0-liter V8 and 6.6-liter turbodiesel are
both mated to a six-speed automatic. The latter works well, and employs a
heavy-duty Allison-made transmission.  We
measured 14 mpg overall with the diesel. The LTZ trim has a luxurious cabin but
ascending to into it is quite a climb. If you don't plan to go off-road, the
Z71 suspension is superfluous -- it makes the ride extremely stiff, bucking
uncomfortably on every bump. The cabin is quiet but the diesel clatter is
audible at low speeds. Handling is clumsy but ultimately secure. The HD pickups
are the better choice for commercial purposes and lend themselves to snow-plowing
duties. Available safety features include forward-collision alert,
lane-departure warning, and front and rear park assist. Apple CarPlay and
Android Auto are compatible with the easy-to-use infotainment system.