Beyond the Vehicle-to-Parts Ratio: A Four-Dimensional Value-Carrier Framework for Diagnosing OEM–Supplier Coordination in China’s Electric Vehicle Clusters

The concept of automotive components, centred on manufacturing output, no longer captures the software, data and computing-power assets that determine advantage in software-defined electric vehicles. Taking China as its setting, this paper asks what a component is once value is generated jointly by parts, code, information and computation. It argues that the vehicle-to-parts ratio has become unusable: the 2025 revision of sub-national vehicle production accounting broke the comparability of city-level data, and components are accounted for as a single manufacturing aggregate in which intangible value is invisible. The ratio therefore remains valid as a measure of localisation but fails as a diagnostic of technological autonomy. The paper develops a four-dimensional framework reclassifying automotive value into hardware, software, data and computing-power carriers, specifies their dependency relations, and operationalises a collaboration ecosystem index with disclosed proxy indicators and an explicit coding rubric. Applied to four Chinese clusters and to Guangzhou, it identifies four coordination modes whose profiles exhibit asymmetric complementarity rather than convergence on one optimum. OEM–supplier coordination shifts from buyer–seller transactions to symbiotic partnership, from local sourcing to network coordination, from hardware to capability procurement and from cost to innovation orientation, with Tier 0.5 integrators as the most consequential structural change.