Additive Manufacturing (AM) has recently experienced increased demand for the production of lightweight aluminium components for EVs, owing to its capability to fabricate complex geometries with high material efficiency. Nevertheless, the sustainability implications arising from the selection of process parameters in laser-based AM have not been adequately examined, with few studies establishing a direct linkage between process-level thermophysical behaviour and environmental performance. This study analyses the sustainability implications of AM-based Direct Energy Deposition (DED) for the production of AlSi10Mg EV motor housings by integrating thermo-mechanical process simulation with Life Cycle Assessment (LCA). Physics-based thermal simulations were conducted for multilayer thin-wall deposition under different combinations of laser power (200-400 W) and scan speed (5-15 mm/s) to predict temperature evolution, residual stresses and laser energy consumption. Analysis revealed a progressive heat accumulation during the build, with maximum temperatures in the initial layers increasing to about 2261 °C. Higher laser power produced consistently larger thermal gradients, while increasing scan speed reduced the magnitude of the gradient across the deposited layers. The predicted residual stress distributions exhibited tensile stresses toward the top of the deposit and compressive stresses near the substrate, reflecting constrained thermal contraction during cooling. Using Simapro, these simulation outputs will be used to generate the process inventory for LCA, including laser energy consumption and residual stresses, to quantify the environmental performance at the manufacturing stage. This approach links process-level simulations with LCA, enabling evaluation of how process parameter selection in laser-based additive manufacturing influences the environmental performance of aluminium EV components