A hybrid rocket motor (HRM) is a type of rocket motor that combines features of both solid and liquid rocket motors. Hybrid rocket motors typically have lower specific impulse than liquid rocket motors, which can limit their performance in certain applications. While most hybrid rocket motors use traditional fuel and oxidiser combinations, this research aims to investigate HRM’s propulsive performance in a novel fuel additive design. The propulsive performance parameters are numerically determined for their characteristics’ velocity, specific impulse, and adiabatic flame temperature. Simulations were run using the Chemical equilibrium with applications-National Aeronautics and Space Administration (CEA-NASA) software. High-entropy alloy (HEA) was doped with paraffin wax at various concentrations to study the effects of the fuel and different oxidisers on the performance of the hybrid rocket. The highest overall performance for all parameters examined was achieved with the lowest HEA content and O2 as the oxidiser.