Biodiesel Improves Engine Operation

Biodiesel, even in very low concentrations, improves fuel lubricity and increases the cetane number of the fuel. Diesel engines depend on the lubricity of the fuel to keep moving parts, especially fuel pumps and injectors, from wearing prematurely. To address the reduced natural lubricity of ultra-low sulfur diesel, Specification ASTM D975 for diesel fuel was modified to add a lubricity requirement (a maximum wear scar diameter on the high-frequency reciprocating rig [HFRR] test of 520 microns). Biodiesel can impart adequate lubricity to diesel fuels with poor natural lubricity at blend levels as low as 1%.