The Lubricity of Winter Diesel Fuels

In the last few years, particularly since the introduction of Low Sulfur Diesel fuel (i.e. containing less than 500 ppm Sulfur), there have been sporadic complaints regarding field failures of rotary or distributor type fuel injection pumps as used in light and medium duty diesel engines. These failures have been typically associated with the use of either “winter” grade diesel fuel or diesel fuels that have been significantly altered due to environmental legislation (i.e. such as has been mandated in Sweden).

Shell Canada has investigated the lubricity of such fuels where “good” lubricity is defined as the ability of a fuel to prevent or minimize wear in diesel fuel injection equipment.

Evaluation methods included:

• actual over the road vehicle tests
• Tests using purpose built fuel pump endurance rigs
• Lab bench tests such as ASTM D5001,Scuffing versions of this test and the High Frequency Reciprocating Rig (HFRR) Test.

Results of this test program are presented and discussed including correlating the field & pump rigs with the lab bench tests.