Viscosity is the most important characteristic of hydraulic fluid and which is influenced by pressure and temperature. Using statistical methods for correlation analysis and regression, eventual causal relationship between parameters of the Arrhenius-type equation and principally the boiling point of some classical Newtonian liquids is attempted. Empirical validation utilizing data on viscosity of pure Newtonian liquids studied at atmospheric pressure and at different ranges of temperature gives excellent statistical results. Indeed, we found a significant strong correlation between the Arrhenius activation energy (Ea), the Arrhenius temperature (TA), and the boiling point (Tb). Consequently, an original hyperbole-type equation modeling this relationship is proposed which allows the prediction of the boiling temperature and the type of isobaric liquid-vapor diagram through information on viscosity Arrhenius parameters values, only in liquid phase, and will be thus very useful in the handling of engineering data especially for the study of hydraulic components and systems efficiency.