<div class="section abstract"><div class="htmlview paragraph">Nanofluids have emerged as effective alternatives to traditional coolants for
enhancing thermal performance in automotive applications. This study conducts a
comparative analysis of the viscosity and thermal conductivity of ZnO and Cu
hybrid nanofluids. Nanofluids were prepared with ZnO and Cu nanoparticle
concentrations of 0.1%, 0.3%, and 0.5% by volume and were characterized over
temperatures ranging from 25°C to 100°C. The results demonstrate that ZnO and Cu
hybrid nanofluids achieve an increase in thermal conductivity by up to 22% and
28%, respectively, compared to the base fluid. Concurrently, the viscosity of
these nanofluids increases by up to 12% at the highest concentration and
temperature. This study addresses a critical research gap by investigating the
combined effects of ZnO and Cu nanoparticles in hybrid nanofluids, an area that
has been underexplored. By providing new insights into optimizing both thermal
conductivity and viscosity, this research contributes to the development of more
efficient cooling systems for automotive applications.</div></div>