The automotive industry is under pressure to meet fuel economy regulations in the future. Smaller and lighter weight cars are inevitable. Designing smaller cars is well underway. Material selection is not as clear-cut.Lightweight materials may or may not prove better than effective utilization of materials and processes currently used. The choice between “light-weight”, e.g., plastic and “heavy” materials, e.g., zinc is evaluated by comparing plastic injection moldings and thin wall zinc die casting. The term “thin wall,” when applied to zinc die castings is used to identify minimum wall thicknesses that will do the job required.