Engine oil is primarily used to carry away the excess heat from engine and to provide lubrication to moving parts of the engine, thereby reducing friction and wear between the rubbing surfaces. However with time net heat stored in the bulk of the engine oil becomes greater than its thermal conductivity causing a drastic reduction in its viscosity leading to formation of oil sludges inside the engine. Previous studies prove that the nano engine oil prepared by dispersing nanoparticles into engine oil provides enhanced operational characteristics when compared to plain engine oil, but are accompanied by the high cost of preparation and low stability of the nano engine oil. In the present study a nano base oil which is a dispersion of MWCNTs and ZnO nanoparticles of ratio 1:4 in mineral oil was prepared by the two step preparation process. Tribological properties such as wear resistance, friction co-efficient and thermophysical properties such as thermal conductivity, viscosity, flash point of the nano base oil were evaluated and were compared with SAE 20W40 engine oil. The results obtained reveal that nano base oil possess better tribological and thermophysical properties when compared to engine oil, which will eventually improve the lifetime of the engine components. Copyright © 2018 VBRI Press.