In this study, the heat transfer performance of [MMI][DMP] ionic liquid solution (20 vol% IL + 80 vol% deionized water) in the presence of Mxene nanoparticle is investigated based on computational fluid dynamics numerical method considering temperature-dependent properties. It should be noted that the thermophysical properties of IoNanofluid were experimentally measured in our previous published study. The modeling results are validated with numerical and experimental works, and the validation results indicate good agreement between them. The effect of adding Mxene nanoparticle to the base liquid was carried out in a horizontal tube with 1–50 range of Reynolds number. The results found that the heat transfer coefficient increased by increasing the Reynolds number and also the nanofluids’ concentration. Moreover, it raises by increasing the fluid inlet temperature while the Nu number decreases. This is because the Nusselt number is in a reverse relationship with the heat transfer coefficient. The maximum heat transfer coefficient observed for 0.2 mass% INf at 308 K fluid inlet temperature and Reynolds number of 50 was 2207.83 W m ² K ⁻¹. However, the maximum Nusselt number detected for pure base fluid at 298.15 K fluid inlet temperature and Reynolds number of 50 was 13.22. Furthermore, the maximum heat transfer enhancement was observed for 0.2 mass% INf at Reynolds number of 50 and 308.15 K fluid inlet temperature (43.6%). Finally, a novel correlation is proposed to estimate the Nusselt number of nanofluids with R ² = 0.992 and AREP = 2.8%.