The tribological effect of lubricating oil on sliding contact as well as its rheological behaviour were investigated. Using a high frequency reciprocating rig (HFRR) tribometer tester, the study applied Eichhornia Crassipes carboxymethyl cellulose (EC-CMC) polymer as an organic additive in corn oil (CO) and sunflower oil (SFO). Base CO and SFO samples were blended with four samples of EC-CMC concentration (0.5%, 1%, and 1.5%) by volume for the study of the viscosity improver index. Rheological studies on the polymer concentrations show good results with 1%, 2%, 3% and 4%, but indicated optimal on 1% EC-CMC especially from temperature beyond 100 o C for the two selected lubricants. Under friction and wear analysis, the test was conducted using 1wt% EC-CMC. The base lubricants CO and SFO yielded friction coefficient and wear scar diameter of 0.087, 11.2 *10 -6 mm 3 /N/m and 0.080, 10.5 * 10 -6 mm 3 /N/m, respectively. During the testing, the use of 1% EC-CMC blended SFO yielded lower coefficient of friction than CO both at base state and inclusion with additive. This produced COF reduction by 22.5% and 13.8% for EC-CMC + SFO and EC-CMC + CO, respectively, but gives better reduction under SAE 5W 30. The analysis concluded that application of 1% concentration of EC-CMC in base oil lubricant for both SFO and CO significantly enhanced the properties. The utilization of this sustainable product certainly will contribute to solving global pollution challenges.