Viscosity of diesel fuel

Diesel fuel prevents wear of high-pressure fuel pumping and injection equipment parts. If the viscosity of diesel fuel is low, its ability to form a hydrodynamic lubricating film between moving metal parts diminishes. The term lubricity is used to describe the wear-inhibiting capability of distillate fuels. 

Viscosity (ASTM D-445, IP 71) is a measure of the resistance to flow by a liquid and usually is measured by recording the time required for a given volume of fuel at a constant temperature to flow through a small orifice of standard dimensions. The viscosity of diesel fuel is important primarily... 

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