In the last few years there have been sporadic complaints regarding field failures of diesel fuel injection equipment. Upon investigation these complaints have been associated with: i) rotary or distributor type pumps as used in light and medium duty diesel engines, and ii) the use of “winter” grade diesel fuels or diesel fuels that have been altered to meet the requirements of environmental regulations. Rotary and distributor type diesel fuel pumps rely totally on the fuel for lubrication. The fuel's ability to prevent or minimize wear in these types of pumps is important. This ability has recently been referred to as the fuel's “lubricity”.Shell Canada has been investigating this issue for the past few years. Recently we have investigated the “lubricity” performance of various diesel fuels using two diesel fuel pump endurance rigs. One rig consists of two rotary type pumps, the other two distributor type pumps. The correlation of the results from these particular rigs to the actual performance of pumps in vehicle field tests has been previously established.Test results from the distributor type pump rig are presented, discussed and related to the test fuel properties, including lubricity as measured in lab bench tests. Test results from the rotary type pump rig will be presented in a later paper.