As 3D printing, also known as additive manufacturing (AM), begins to replace conventional manufacturing, the environmental impacts of its implementation must be assessed. This study conducted a life cycle assessment (LCA) to investigate the environmental and resource implications of using AM to manufacture the metal parts of an engine in a light distribution truck. In the LCA, the impacts of both present and possible future states of AM technology were compared with current conventional manufacturing. The results suggest that there are potential environmental and resource benefits1 to AM technologies, but that these benefits rely on the achievement of a clean energy source and further technological development.