This paper focuses on optimizing the design of an eco-car chassis cross-section. This is done by constructing design maps and by carrying out a parametric study on the relative stiffness and mass of three different cross-sections: round-tubular, square-tubular and I-section. The objective is to determine the section that yields the desired safety factor while maintaining the lowest possible mass. An iterative approach is employed and the safety of the final design is verified both numerically and experimentally.