The imperative to improve energy utilization in the automotive sector has led to the development of various aimed at increasing this review of five energy recovery systems … vehicle performance and sustainability amidst the rise of electric and hybrid technologies. Regenerative braking, mechanical flywheels, thermoelectric generators, Rankine cycles, and electric turbochargers were employed modeling and analytical techniques, assessing their impact on The Rankine cycle and electric turbochargers, in particular, offer significant improvements by employing modeling and analytical techniques, optimizing waste heat recovery, and reducing turbo lag, respectively. Regenerative braking and mechanical flywheels further contribute by recycling kinetic and rotational energy to enhance fuel efficiency. Thermoelectric generators convert waste heat into electricity, increasing overall vehicle energy efficiency. In conclusion, despite the inherent limitations in achieving perfect efficiency, the synergistic application of these systems promises substantial gains in efficiency and emission reduction.