The GMC Sierra comes in a dizzying array of trims. Four engines, three transmissions, 4x2 and 4x4, three box lengths . . . there’s no end to the choices! The base engine is a 4.3L V6, though three V8s are also available, including a 6.0L for the hybrid versions. Only the hybrid gets a CVT transmission; the others come with either a 4- or 6-speed automatic. It is also one of the most reliable trucks on the market.