Reducing vehicle mass has a direct impact on energy consumption, emissions, and driving range, particularly for electric vehicles. In modern automotive body design, material selection is no longer driven solely by mechanical strength but requires a balanced consideration of weight, stiffness, cost, crash performance, and recyclability.

This study presents a comparative analysis of steel, aluminum alloys, and carbon fiber reinforced polymer (CFRP) composites used in automotive structures, focusing on mechanical performance, mass, cost, and environmental impact. A representative body structure component is modeled in a CAD environment and evaluated using finite element analysis (FEM) in ANSYS. The materials are assessed under bending and compression loading conditions, with emphasis on stress distribution, deformation, and strength-to-weight ratio.

An analytical model based on classical beam theory is developed to validate the numerical results and to quantify the differences between theoretical predictions and FEM simulations. In addition, an economic evaluation is performed, including material and manufacturing costs, together with a Life Cycle Assessment (LCA) to estimate environmental impact.

The results highlight the advantages and limitations of each material according to the analyzed criteria. Steel provides a robust and economical solution but incurs a mass penalty; aluminum ensures an optimal compromise between weight reduction and cost, while CFRP composites achieve superior structural performance at the expense of higher costs and limited recyclability.

The main contribution of this work is the development of an integrated comparative framework combining analytical modeling, numerical simulation, and economic assessment, providing a practical decision-support tool for material selection in automotive structures. The proposed approach is applicable to both engineering design and production optimization under current requirements for energy efficiency and sustainability.