The piston ring axial motion model developed by Furuhama, Dowson and Hoult was modified using the parallel plate squeeze equation to account for oil in the ring grooves. The improved model was used to predict ring motion and the ring transition time from one ring land to the other. The ring axial motion was measured in detail on an engine with a clear plexiglas cylinder using a high-speed motion picture camera. The observed ring motion and transit times were compared to those predicted by the new model. The model was found to correctly predict the motion of the rings and the scaling with lubricant viscosity and engine speed.