Fuel economy requirements, emissions regulations, and the push for energy independence are key factors driving the auto industry to increase vehicle efficiency. The main avenues to efficiency improvement are powertrain enhancements and mass reduction. This talk will detail how GM is using lightweight materials such as aluminum and magnesium alloys, high-strength steels, and composites to reduce vehicle weight. It will also highlight how GM is employing novel materials in the development of advanced vehicle and powertrain systems to achieve additional efficiencies. One example is the application of smart materials, which today are approaching automotive cost at volume. Smart materials enable new features and functions via mechamatronic solutions (the integration of smart materials with mechanical systems and electronics). Key technical hurdles that must be overcome to increase the use of advanced materials by the industry will be discussed.