Life cycle assessment of diesel, e-diesel, and hydrotreated vegetable oil for passenger cars

Biofuels and electrofuels (e-fuels) are among the proposed options allowing the continued sale of new internal combustion engine light-duty vehicles beyond 2035. However, their environmental performance is still predominantly assessed through climate change indicators, overlooking potential burden shifting towards other impact categories. This study presents a comparative Life Cycle Assessment of a passenger car fuelled with fossil diesel, Fischer-Tropsch synthetic diesel (e-diesel), and hydrotreated vegetable oil (HVO), integrating experimentally measured exhaust emissions and applying both well-to-wheel and cradle-to-grave (CtG) perspectives. E-diesel and HVO reduce climate change impacts relative to diesel (13–57%), with fuel-related processes representing the main contributors also in CtG. Improvements are limited across remaining impact categories (4/15), evidencing burden shifting; nevertheless, single-score results indicate lower overall impacts for both alternative fuels. The CtG perspective highlights the relevant contribution of vehicle and road infrastructure, showing that mitigating the environmental impacts of passenger cars cannot rely on fuel substitution alone.