This document discusses the structural analysis of different cross-section designs and composite materials for an automotive chassis to reduce weight. The chassis of an existing heavy vehicle is modeled and analyzed using various polymer composite materials (carbon/epoxy and S-glass/epoxy) and cross-sections (C, I, box). Numerical analysis is performed and results are validated against analytical calculations. Analysis shows that a carbon/epoxy composite chassis with an I-cross section induces lower deformation and stress compared to other materials and designs, making it superior for withstanding high loads.