The hydrodynamic thrust bearings has been the subject of several studies in the scientific environment. In the hydrodynamic lubrication the surfaces are completely separated by the lubricating film, and therefore it is the most desirable type of lubrication. The lubricant should be chosen in order to reduce power losses by viscous dissipation. The work aims to analyze the power loss by viscous dissipation for various types of lubricating oils. It was investigated a six pivoted-pad thrust bearing in a rotation range between 1500 rpm and 3000 rpm. Eleven different types of lubricating oils were analyzed. It was possible to observe the net power loss - in function of the lubricant type - for each of the thrust bearings located in an automobile. The cost associated with this loss of potency was also obtained. The results showed that the appropriate selection of the lubricating generates an increase of 50% in power gain.