Researchers have compiled the most comprehensive overview to date of life cycle assessments (LCAs) of vehicle components, drawing on 160 individual case studies published between 1995 and 2024. The systematic literature review, conducted by Kai Rüdele, Michael Kovačič, Christian Ramsauer and Roh Pin Lee and published in European Transport Research Review, screened 834 publications down to 129 records and analysed how the automotive supply industry has measured the environmental footprint of specific parts, from body panels and engines to seats and wiring.
The review deliberately excluded two components that already have dedicated bodies of research: traction batteries and tires. Both have been studied so extensively, and summarised in existing systematic reviews, that the authors judged an additional synthesis would add little. What remained was a gap the authors describe as previously unfilled: no comprehensive scientific overview of component-level LCAs existed, even though a modern car such as the Volkswagen Golf 8 contains just over 2,700 individual parts and 1,340 metres of cable across 962 wiring systems, 31 more wiring systems than its predecessor.
The search combined Google Scholar and Scopus with a snowballing approach that mined reference lists, plus AI-assisted searching and hand-searching, which together added fifteen further peer-reviewed articles. The final sample comprised 111 journal papers, 13 conference papers, three reports and two book chapters. Publication activity showed a slight upward trend until 2021, though the number of new studies declined after peaking in 2020, a pattern the authors note is too recent to draw final conclusions from.
Structural parts dominated the sample, accounting for nearly half of all LCAs with 74 cases from 55 publications. These include bodywork, exterior components such as closures, panels and bumpers, and chassis and suspension parts. Powertrain components, covering engines, transmissions, exhaust systems and brakes, ranked second with 33 cases, followed by interior components such as seats and dashboards with 22. Electrical and electronic components and materials such as composites each contributed nine cases.
Methodologically, the review found a strong preference for attributional LCAs, with only one publication addressing consequential aspects through system dynamics. Five publications were full life cycle sustainability assessments integrating environmental, economic and social dimensions, while combining environmental LCA with life cycle costing appeared in roughly ten percent of cases. Cradle-to-grave scope, covering raw material extraction through end-of-life treatment, was the most adopted boundary at 74 percent of cases. For functional units, authors preferred counting components, using a number-based reference in 70 percent of cases, with distance-based references at 15 percent and mass-based units at just 7 percent.
Climate change, measured as global warming potential, emerged as the most frequently assessed impact category across all component groups. Energy demand, reported as primary or cumulative energy consumption, was also dominant, particularly for powertrain components. Water consumption and pollution, by contrast, were comparatively rarely considered. The CML method led among life cycle impact assessment approaches at 19 percent of cases, followed by IPCC at 14 percent, which focuses solely on global warming potential. Earlier studies often reported substances, air emissions or solid waste rather than standardised impact categories, but by around the turn of the millennium today’s common standards and terminology had been adopted.
In terms of content, lightweighting is the central theme, discussed in nearly every second case. Material substitution drives most of these comparisons, with the shift from steel to light metals, predominantly aluminium and sometimes magnesium, examined more often than substitution with fibre-reinforced plastics. Most comparative studies used break-even analysis, identifying the mileage at which an alternative becomes environmentally preferable. Around six percent of cases dealt with bio-based or biodegradable materials, and five percent assessed additive manufacturing. Circular economy processes such as remanufacturing and recycling appeared only rarely, a gap the authors contrast with complete-vehicle and battery studies where circularity already plays a prominent role.
The bibliometric analysis showed that researchers in the United States produced the most publications as first-author affiliations, with 26, or one-fifth of the sample, followed by Italy with 17 and China and Germany with 13 each. Considering all co-author affiliations, European countries demonstrated the highest overall output. Gregory Keoleian of the University of Michigan emerged as the most prolific author, and the University of Michigan was the most productive institution with eleven publications. The Journal of Cleaner Production led the source journals with 23 articles. The authors also note that key automotive manufacturing countries including Mexico, South Korea, Taiwan, Turkey, France and Indonesia play a minimal role in the sample.
The review documents growing professionalisation over time: standardised ISO 14040-based methodology, common impact categories, sensitivity analyses from the early 2000s onwards and Monte Carlo simulations from around 2010. Nearly 30 percent of cases included scenario, sensitivity or Monte Carlo analysis. Yet limitations remain. The search was restricted to two databases, English-language publications and manual screening, so the authors caution that studies on exhaust systems or headlights, for which no LCAs were found, may simply have been overlooked. Heterogeneous functional units and system boundaries also hinder direct comparison between similar components, meaning results should always be interpreted in light of their defined scope.
Subject of Research: A systematic literature review of life cycle assessments of vehicle components, excluding batteries and tires, covering 160 case studies published between 1995 and 2024.
Article Title: Life cycle assessments of vehicle components: an overview
Article References: Rüdele, K., Kovačič, M., Ramsauer, C., & Lee, R. P. (2026). Life cycle assessments of vehicle components: an overview. European Transport Research Review, 18(1), Article 103. https://doi.org/10.1186/s12544-026-00857-7
Image Credits: AI Generated
DOI: 10.1186/s12544-026-00857-7
Keywords: life cycle assessment, vehicle components, automotive industry, lightweighting, systematic literature review, climate change, material substitution, cradle-to-grave, bibliometric analysis, sustainability, Life, cycle
News Source: Sloane Callahan. (October 30, 2026). Nearly Three Decades of Vehicle Part Life Cycle Assessments, Mapped in One Review. Scienmag.
