A sliding wear model has been developed for partial-EHL contacts, in which both the thermal desorption wear mechanism at low asperity contact temperature and the oxidative wear mechanism at elevated asperity contact temperature are considered. To include micro-EHL effects, digitized actual surface roughness profiles are used in simulating two contacting rough surfaces, and in obtaining the asperity contact area and asperity contact temperature distributions within a Hertzian contact region. Wear measurements in a two-disk machine configuration have been made over a comprehensive range of slide-to-roll ratios. The experimental results show a continuous decrease in wear rate with the increase in slide-to-roll ratio when the slide-to-roll ratio is relatively small, and a drastic rise in wear rate when slide-to-roll ratio is further increased. The experimental wear rate curve as a function of slide-to-roll ratio verifies the model prediction. The drastic rise in wear rate with the increase in slide-to-roll ratio in the range of slide-to-roll ratio beyond unity seems to suggest that a transitional phenomenon exists in the relation between wear rate and slide-to-roll ratio.