In order to prevent warming and deterioration in the surface condition of the plain bearing (shaft/bearing), it was necessary to enhance the heat engines' efficiency by applying a coating containing 88% tin to the internal surface of the bearing. To assess the effectiveness and reliability of these coatings, a testing rigs specifically designed for automotive engine bearings was developed. The University of Poitiers collaborated on the experimental analysis, which explored the impact of different loads and speeds. The results of the analysis confirmed that frictional efficiency tended to improve with low loads and high speeds. The displacement observed in the bearing decreased as the speed increased, particularly in lightly loaded plain bearings. Conversely, heavily loaded sliding bearings exhibited higher displacement values. At the 315º position, the displacement was particularly significant and increased significantly with the load, while it was less significant at the 45º position. In the 315º position, the circumferential face displacement of the shaft decreased notably with increasing speed at low loads. Similarly, for higher loads, the displacement only slightly decreased with increasing speed, but these displacements were very high at the 315º position.