GM’s latest pickup-truck twins, the Chevrolet Silverado and GMC Sierra, were completely redesigned this year, and the company opted for a slow, painstaking rollout of the trucks’ details, as well as output figures and fuel economy for the rigs’ 4.3-liter V-6, 5.3-liter V-8, and 6.2-liter V-8 engines. At long last, the slow tide of information [...]