(S&T)2 has conducted a critical review for the ART Fuels Forum (AFF) of the study ‘Determining the environmental impacts of conventional and alternatively fuels vehicles through LCA’ that was commissioned by the European Commission’s DG Climate Action.  The stated aim of the study was to improve the understanding of the environmental impacts of road vehicles and the methodologies to assess them in the mid- to long-term timeframe (up to 2050). It covered a selection of light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs) with different types of powertrains (internal combustion engine and/or electric engine powered by fuel cells or batteries) and using different types of energy (of fossil and/or renewable origin). The (S&T)2 critical review focussed on the fuel supply chains.