Pour point is an important quality specification for diesel fuels. Specifically, it is a measure of the tendency of a fuel to become more viscous and resist flowing when cold.
Pour point is measured as 5F 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.