This invention relates to a diesel fuel composition comprising a major amount of a base fuel and a relatively minor amount of at least one chemical component other than that generated in a refinery process stream which component is miscible with the base fuel in such proportions that the T30 temperature of the resultant composition is in the range from 205-240° C. The control of the T30 temperature within the specified range by blending with the minor component results in a significant reduction in particulate emissions.