Proposal to establish a new Mutual Resolution concerning Automotive Life Cycle Assessment (A-LCA) to provide an internationally harmonised methodology for determining the carbon footprint of light-duty vehicles across all life cycle stages—material production, parts production and vehicle assembly, use, and end-of-life—considering energy use pathways from production to disposal, with a Level Concept offering four detail levels depending on data availability and study purpose, including definitions, abbreviations, system boundaries, data collection requirements, energy modelling approaches for electricity and fuels, allocation rules, waste treatment and recycling modelling using Circular Footprint Formula or Recycled Content Method, maintenance assessment, and verification procedures. The methodology applies to light-duty vehicles, uses a functional unit of 1 passenger per kilometre over vehicle lifetime, includes service life values from official data by Contracting Parties or peer-reviewed reports, accounts for discrepancy and deterioration factors in use phase calculations, addresses traction battery and fuel cell deterioration, specifies reporting requirements for all life cycle stages including biogenic emissions separately, and requires external third-party verification for Level 3 and Level 4 studies based on GRPE/86/Rev.1 through the Working Party on Pollution and Energy at its 93rd session.