Hybrid nanofluids demonstrate superior thermophysical properties compared to pure nanofluids, offering enhanced thermal conductivity, mechanical strength, and stability. This investigation examines the thermal and magnetic characteristics of both pure \(\text {Al}_2\text {O}_3\) /engine oil (EO) and hybrid \(\text {Al}_2\text {O}_3\) - \(\text {Fe}_3\text {O}_4\) /EO nanofluids under the influence of applied and induced magnetic fields. The analysis incorporates the effects of activation energy and chemical reaction kinetics. We develop an innovative numerical solution approach employing order reduction techniques implemented via the bvp4c solver. Validation against established results demonstrates excellent agreement, confirming the method’s robustness. Key findings reveal that increasing Grashof numbers enhances both vertical and horizontal velocity components, while the induced magnetic field parameter exhibits an inverse relationship with fluid velocity in both pure and hybrid systems. Furthermore, nanoparticle volume fraction shows a positive correlation with temperature distribution. The results suggest that hybrid \(\text {Al}_2\text {O}_3\) - \(\text {Fe}_3\text {O}_4\) nanofluids present significant advantages for thermal management applications, combining improved heat transfer performance with inherent corrosion resistance properties. These characteristics position hybrid nanofluids as promising candidates for advanced thermal engineering systems.
