Engine oil functions as the lifeblood of engine providing lubrication, and protecting the engine against failure and corrosion (Barnes et al. 2001; Basu et al. 2000). Engine oil samples are analyzed to determine the condition of oil and supervise the health of machines. Oil degradation is assessed by analyzing oil quality against the serviceability of oil. The current study was focused on determining whether the engine oil sampled periodically and infrequently by NCDOT for the purpose of monitoring the health of individual machines could be used to evaluate the rate of oil degradation. Therefore, the oil quality measures were obtained and regressed against each calculated oil age parameter to evaluate the relationship for the selected equipment classes. The analysis results indicated that a significant relationship between oil quality and oil age was not observed from the data collected and analyzed. The research was challenged by insufficient analyses data as the equipment classes for analysis were selected based on the number of oil analyses results and the classification of equipment. The equipment classification was limited to the availability of preventive maintenance records and the determination of oil age parameters. The study concludes that engine oil sampled periodically and infrequently for the purpose of monitoring the health of individual machines do not serve the purpose to determine the rate of oil degradation for the given classes of machines.