Yttrium Iron Garnet (YIG) doped with rare-earth elements have shown to alter the magnetic properties of garnet nanoparticles (NPs), which is believed to have direct influence on the wettability, interfacial tension and viscosity alteration of garnet nanofluids. In this study, Y 2.8 R 0.2 Fe 5 O 12 (R = Lanthanum (La), Neodymium (Nd) and Samarium (Sm)) NPs were synthesized by using the sol gel auto-combustion method followed by annealing treatment at 1000°C for 3 hours. The Y 2.8 RE 0.2 Fe 5 O 12 nanoparticles synthesized had grain size ranging from 100 to 200nm with high crystallinity properties. X-ray Diffraction peaks showed varying shifting with the size of the rare-earth ions in the Y 2.8 R 0.2 Fe 5 O 12 crystal system, suggesting that structural distortion is due to replacement of bigger ions. Sm-YIG exhibited the highest magnetization saturation among all samples, with the value of 23.54 emu/g. Wettability data of Y 2.8 R 0.2 Fe 5 O 12 (RE-YIG) nanofluids showed that oil-wetting contact angle has an overall reduction under the influence of electromagnetic wave. Whereas the interfacial tension and viscosity data showed that doped garnet nanofluids has lower value than that of garnet nanofluids, but the magnitude of interfacial tension and viscosity value decreased with the rare-earth ionic size. Sm-YIG also has the highest interfacial tension across all samples, as the stronger magnetization saturation may contribute to higher surface tension exerted on the oil-nanofluid interface.