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M-1A-14 - Lightweighting of Vehicles

Lightweighting of vehicles involves reducing the overall weight of vehicles to enhance fuel efficiency and decrease greenhouse gas emissions. By using advanced materials such as high-strength steel, aluminum, carbon fiber, and composites, manufacturers can reduce the mass of vehicles without compromising safety or performance. Lighter vehicles require less energy to accelerate and maintain speed, leading to improved fuel economy and reduced emissions in both conventional and electric vehicles.

Lightweighting of vehicles is outlined in box 10.3 of (IPCC AR6 WG3 2022)1.

Mitigation Objective

The primary goal is for an efficiency shift to improve the fuel efficiency of light-duty vehicles.

Mitigation Potential

Potential

The AR6 report and the literature referenced by it do not present any conclusive estimates for the mitigation potential of lightweighting of ICE vehicles.

Lightweighted components often have higher production emissions than the components they replace due to the advanced materials used (Kim and Wallington 2016). Despite these higher production emissions, some studies suggest that the reduced fuel consumption over the lifetime of the lightweighted vehicle may provide a net mitigation effect in comparison to a non-lightweighted vehicle (Kim and Wallington 2013; Hottle et al. 2017; Milovanoff et al. 2019; Upadhyayula et al. 2019; Wolfram et al. 2020). However, multiple recent publications have found that in some cases, depending on, for example, vehicle size and carbon intensity of the lightweighting materials employed, the GHG emissions avoided due to improved fuel efficiency do not offset the higher manufacturing emissions of the vehicle (Luk et al. 2018; Wu et al. 2019).

- (IPCC AR6 WG3 2022)1

The current harmonization shows that whether lightweighting reduces life cycle energy demand and GHG emissions depends on material source and process type or inventory data source for these materials. Given the flexibility in options implied by the variety of materials available and the broad consensus that they have energy and emissions benefits (see Figure 4), we conclude that lightweight materials (particularly Al, GFRP, and HSS) are likely to see increased use in automobiles.

- (Kim and Wallington 2013)2

Our model estimates that implementation of an aggressive lightweighting scenario using aluminum reduces 2016 through 2050 cumulative life cycle GHG emissions from the fleet by 2.9 Gt CO₂-eq. (5.6%), and annual emissions in 2050 by 11%. Lightweighting has the greatest GHG emissions reduction potential when implemented in the near-term, with two times more reduction per kilometer traveled if implemented in 2016 rather than in 2030.

- (Milovanoff et al. 2019)3

The extent to which life cycle GHG emissions are reduced from vehicle lightweighting depends on powertrain type. This is in large part because vehicles with different powertrains have different fuel cycle GHG emissions and thus potential reductions from lightweighting. Therefore, lightweighting an ICEV results in greater GHG emissions mitigation (base case result: 10 t CO₂-eq.) than lightweighting a more efficient HEV (base case result: 6 t CO₂-eq.).

- (Luk et al. 2018)4

Modelling

This mitigation method is not currently modelled with any Transition Elements.

Primary Reference

The primary reference for this mitigation measure is (IPCC AR6 WG3 2022)1.

Secondary References

TBD

  1. IPCC AR6 WG3. 2022. Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by Priyadarshi R. Shukla, Jim Skea, Raphael Slade, Alaa Al Khourdajie, Renée van Diemen, David McCollum, Minal Pathak, et al. https://doi.org/10.1017/9781009157926. ↩↩↩

  2. Kim, Hyung Chul, and Timothy Wallington. 2013. “Life-Cycle Energy and Greenhouse Gas Emission Benefits of Lightweighting in Automobiles: Review and Harmonization.” Environmental Science & Technology 47 (May). https://doi.org/10.1021/es3042115. ↩

  3. Milovanoff, Alexandre, Hyung Chul Kim, Robert De Kleine, Timothy Wallington, Ira Posen, and Heather Maclean. 2019. “A Dynamic Fleet Model of u.s Light-Duty Vehicle Lightweighting and Associated Greenhouse Gas Emissions from 2016-2050.” Environmental Science & Technology 53 (January). https://doi.org/10.1021/acs.est.8b04249. ↩

  4. Luk, Jason, Hyung Chul Kim, Robert De Kleine, Timothy Wallington, and Heather Maclean. 2018. “Greenhouse Gas Emission Benefits of Vehicle Lightweighting: Monte Carlo Probabalistic Analysis of the Multi Material Lightweight Vehicle Glider.” Transportation Research Part D Transport and Environment 62 (July). https://doi.org/10.1016/j.trd.2018.02.006. ↩

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