Due to its exceptional mechanical and crashworthiness properties, lightweight nanocomposites have recently been used more and more in aviation, defense, nautical, and automotive applications. Nanocomposite cylinders could be effectively employed in this respect as energy-absorbing components for decreasing the impact energy during vehicle crashes. The current work examined the crashworthiness response of nano-alumina (Al2O3) filled glass fiber reinforced epoxy (GFRE) composite tubes using quasi-static lateral compressive loads. Crushing profiles and crush force–deformation curves of all representative samples were recorded and discussed. The total absorbed energy (AE) and specific absorbed energy (SEA) for tested specimens were assessed. Furthermore, a multi-attribute decision making (MADM) technique known as complex proportional assessment (COPRAS) was used to compute the optimum nano-Al2O3 wt%. Based on the experimental results, the addition of 1, 2, and 3 wt% of nano-Al2O3 enhanced AE by 7.69%, 18.14%, and 51.21% and SEA by 3.43%, 13.98%, and 39.84%, respectively. While deteriorations of 6.59% and 17.41% in AE and SEA, respectively, were recorded with the addition of 4 wt% of nano-Al2O3. Overall findings showed that (GFRE) composite tubes with 3 wt% of nano-Al2O3 have a special potential to absorb energy.