The four metals -- chromium, molybdenum, nickel, and tungsten -- so important to automotive manufacture, currently are in ample supply. Their availability is well supported by world resources and reserves. There are some hazards from hostilities denying access to remote sources, or political factors hindering efficient mining and transport from some producing countries. Future demand can be expected to grow with an increase in the number of motor vehicles produced, but this trend should be countered by their more efficient use. They are among the more expensive raw materials consumed in automobile manufacture and as such will be a target for redesign by automotive engineers. On the other hand, greater quantities may be needed with refinement in vehicle design.