In response to ever more challenging global fuel economy and environmental regulations, automakers will rely on lightweighting to continue to meet the established goals. As “bolt-on” sub-assemblies, closure panels provide a unique opportunity to tailor the vehicle mass to achieve local environmental compliance relative to a global vehicle platform while maintaining equivalent functionality and safety performance. This paper is aimed at communicating the results of a life cycle assessment (LCA) study which compares the lightweight auto parts of the new Magna’s Ultralight Door design to the conventional auto parts of the baseline 2016 MY Chrysler 200C 6 cyl, 3.6 L, automatic 9-spd, an ICE vehicle (gasoline fueled) built and driven for 250,000 km in North America. Magna International Inc., in cooperation with the U.S. DOE and partners Fiat Chrysler Automobiles (FCA) US and Grupo Antolin, developed a new ultralight door architecture in 2017. The holistic design approach included the development and functional integration of an aluminum door structure with fiber reinforced composite door module and interior trim, Corning chemically toughened Gorilla® glass, while maintaining functionality and safety performance of the 2016 baseline door. Overall, the mixed material combination resulted in a mass reduction associated with the driver’s side door design of 15.2 kg, which results to a potential full vehicle mass reduction of 49.5 kg for a 4-door vehicle versus its Baseline 4-door. Ultralight door applies to approximately 70 per cent of the C, D, E and F light-vehicle market. Magna’s Ultralight door LCA study is conducted in accordance with International Organization for Standardization (ISO) standards 14040/44 and follow the specific rules and guidance provided in the CSA Group 2014 LCA Guidance document for auto parts.