Like all its rivals, GMC has pickup trucks in its catalog. Two quite different vehicles are grouped under the name Sierra: the first, the Sierra 1500, is an alternative to large SUVs; the second, Sierra HD, is almost to be classified in the category of heavy vehicles, since it can carry 3.4 tons. The engines are varied: 4-cylinder turbo and turbodiesel, V8 petrol with displacements ranging from 2.7 to 6.6 liters.