Impact attenuators are passive safety components that are developed to protect the structural elements of the vehicle and the people inside it. In this study, an impact attenuator is designed for Formula SAE (Society of Automotive Engineering) competition racing car. Due to the SAE regulations, the impact attenuator must absorb 7350 J of collision energy in a frontal collision at a speed of 7 m/s, without resulting in any deformation to the vehicle structural elements. Numerical simulations are performed using ANSYS Workbench finite element software. The material model for the impact attenuator is selected as AA6061-T6 aluminum alloy due to its high energy absorption performance. It is found that the design with varying wall thickness to be the most efficient in terms of crash force efficiency and specific energy absorption when compared to the basic conical impact attenuator design. A reduction of 64.99% on the maximum impact force, an increase of 58.76% deformation, and an increase of 30.77% crash force efficiency were achieved between the first design and the final design with varying thickness.