Nanofluids are potential heat transfer fluids due to the flexibility associated with the customization of thermophysical properties. In the present paper, the effect of working fluid on the thermal Conductivity of Silicon Carbide (SiC) nanoparticle suspensions is determined experimentally at temperature of 40, 45 and 50°C. Three different working fluids, viz., Distilled Water (DW), a mixture of Ethylene glycol and Distilled water in the ratios of 20:80 and 40:60 (20:80 EG-DW and 40:60 EG-DW) are considered to prepare SiC nanofluid in the particle fraction ranging from 0.02% to 0.08% by volume. For the same particle concentrations of SiC suspensions, a significant enhancement in thermal conductivity is observed. DW based SiC nanofluid has exhibited higher thermal conductivity whereas 40:60 EG-DW based nanofluid exhibited lower thermal conductivity among the nanofluids considered. The thermal conductivity of DW based SiC nanofluid is 1.005 times that of 20:80 EG-DW and 1.17 times that of 40:60 EG-DW based SiC nanofluids 0.08% particle concentration and at temperature of 450C. The relative thermal conductivity of DW based nanofluid has exhibited a lower enhancement compared to the EG-DW based SiC nanofluid.