Ultralight Vehicles

The research paper by the Rocky Mountain Institute (RMI) challenges the perception that lighter vehicles are inherently less safe by virtually modeling an 'UltraLight' concept vehicle. Through crash simulations and comparisons with a 2007 Ford Edge, the study demonstrates that while an early-stage ultralight design may offer less protection to its own driver than a heavy vehicle, it is significantly less aggressive toward other road users. The findings suggest that a transition to a lightweight fleet could reduce overall injuries and that safety is primarily a function of design and materials rather than mass.

• The RMI UltraLight concept vehicle, a 900-kg midsize SUV, is over 50% lighter than the 2007 Ford Edge while maintaining equivalent size and cargo capacity.
• In side impact simulations, the UltraLight achieved a lower head injury criterion than the Ford Edge, despite experiencing higher accelerations due to its stiffer structure.
• Ultralight vehicles are significantly less aggressive in collisions; partner vehicles colliding with the UltraLight experienced 93 percent fewer injuries than those colliding with the Ford Edge.
• A hypothetical fleet consisting entirely of ultralight vehicles would experience 29 percent fewer overall injuries (14.1 ELUs) compared to a fleet consisting entirely of heavy vehicles like the Ford Edge (19.8 ELUs).
• The UltraLight's low center of gravity, resulting from less mass near the roof, makes it 31 percent less likely to roll over than the Ford Edge.
• Initial simulations showed the UltraLight offered less protection to its driver than the Ford Edge, but minor design changes to seating, headrests, and airbag deployment reduced the UltraLight's equivalent life units (ELUs) by an average of 20 percent without adding weight.

APA

Chan-Lizardo, K., Lovins, A. B., Schewel, L., & Simpson, M. (n.d.). Ultralight Vehicles. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2008-24_UltralightVehicles.pdf

Chicago

Chan-Lizardo, K, A B Lovins, L Schewel, and M Simpson. Ultralight Vehicles. RMI, n.d. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2008-24_UltralightVehicles.pdf.

Wikipedia

{{cite report |last1=Chan-Lizardo |first1=K |last2=Lovins |first2=A B |last3=Schewel |first3=L |last4=Simpson |first4=M |title=Ultralight Vehicles |publisher=RMI |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2008-24_UltralightVehicles.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{chanlizardondultralight, author = {Chan-Lizardo, K and Lovins, A B and Schewel, L and Simpson, M}, title = {{Ultralight Vehicles}}, institution = {RMI}, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2008-24_UltralightVehicles.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }