Inlet pressure effects on the thermohydrodynamic performance of a 4-pad large tilting pad journal bearing are investigated both theoretically and experimentally. The theory takes into account the inlet pressure and the three-dimensional variation of oil viscosity and eddy viscosity. Film pressure, film thickness, bearing metal temperature, load capacity, and eccentricity are measured by experiments. A noticeable inlet pressure rise is observed at the entrance of pads. It is shown that the inlet pressure increases not only the film pressure and the load capacity but also the supply flow rate, while if decreases the mixing and bearing surface temperature. The bearing characteristics predicted by the turbulent thermohydrodynamic theory, including the inlet pressure, are in good agreement with the experimental results. Therefore it can be suggested that the inlet pressure must be taken into account in theoretical calculations in order to predict the thermohydrodynamic performance of large tilting pad journal bearings accurately.