Studies on hydraulic motors have shown that optimizing friction in boundary lubrication can
significantly improve hydraulic motor efficiency [10,11]. It is critically important to ensure efficient
lubrication in order to avoid equipment failures. Failures in boundary-lubricated contacts are generally
avoided or reduced by using suitable and efficient lubricating additives [12]. The quality of the
lubricating oil is essential for the preservation of the action and the longevity of machines. During the
use of hydraulic oils in engines and machines in general, contamination can occur. Those contaminants
interfere directly with the viscosity of the oil, lowering its performance characteristics. These
interferences can lead to mechanical waste and can cause irreversible damage to the mechanical
equipment