This paper aims to classify oil samples using the Metamaterial (MTM) unit cell as a sensor. The S-shaped broadside coupled Split-Ring Resonator (SRR) acts as an MTM and is designed to operate at X-band (8-12.4 GHz). The proposed MTM unit cell was simulated through the High Frequency EM simulation tool, and then the MTM properties were extracted using the standard equations. The MTM behavior was studied through its negative permittivity and permeability characteristics in the X-Band. The simulated and extracted properties exhibit that the proposed MTM unit cell is suitable for the analysis at X-band. A sample container was designed to hold the different oil samples. The experimental analysis was carried out by filling the container with different oils without/with an MTM sensor. Mainly, the variations in S-parameters magnitude were studied for classification applications. This paper proposes the study of transmission coefficients phase response in addition to magnitude as an easy way to classify different oils. Further, the phase transition results were compared with the kinematic viscosity and refractive index properties of the oil sample. The comparison results proved that the classification of oil samples using the phase transition approach agrees well with the existing oil properties.