Pour point is an important quality specification for diesel fuels. Specifically is a measure of the tendency of a fuel to become more viscous and resist flowing when cold.

Pour point is measured as 5 degrees F above the temperature at which a fuel ceases to flow due to the formation of wax crystals that increase its viscosity.

Pour point specifications are a maximum allowable temperature. Lower pour point material is more desirable.

Generally, light (lower boiling point) material will have a lower (more desirable) pour point.