A computer model was developed to investigate the tribological performance of the blade and liner interface in a transfer pump lubricated with diesel fuel. A mixed lubrication model was used due to the low lubricity of diesel fuel. Film thickness and friction at the blade/liner interface were analyzed to evaluate the effectiveness of component design effects on lubrication enhancement. Surface roughness effects on blade and liner interface was also investigated by incorporating die Average Flow Model into the Reynolds Equation. Results indicate that the film thickness at the blade/liner interface is generally lower than the surface roughness level. Reducing die surface roughness has a significant effect in improving film thickness-to-surface roughness ratio. Increasing the blade surface radius also greatly improves the film parameter and reduces the interfacial friction by as much as 80 percent. Effects of blade surface profile changes due to sliding wear were investigated. Results show that friction loss increases as wear volume decreases.