Thermophysical characteristics of MWCNT-ZnO (30–70%)/SAE40 hybrid nanofluid (HNF) using knowledge management cycle and RSM in different solid volume fractions (SVFs), temperature and shear rates (SRs) have been investigated. Emphasis on knowledge management through the use of fast and high-precision methods has led to the use of the RSM for modeling the viscosity of HNF. Different models such as linear model, 2FI, Quadratic, Cubic, Quartic, Fifth and Sixth models are presented. Fifth order model is better than others. Values of R2, Predicted R² and Adjusted R² for all three parameters are 0.9998, which displays good precision of the modeling. The knowledge management cycle is used to evaluate the model to increase sufficient confidence. Examining the matching graphs, deviation coefficient and standard deviation parameters displays good precision of modeling. MOD value is also within ± 2%. With the help of knowledge management in finding the best mode, the optimal viscosity value is equal to 209.53 mPa.sec in temperature, SVF and SR, respectively 31.156 °C, 0.063 % and 933.923 s−1.