This paper presents densities and viscosities of binary mixtures of 1-pentanol + 2-pentanol, 1-pentanol + 2-methyl-1-butanol, and 2-pentanol + 2-methyl-1-butanol from (288.15 to 328.15) K over the entire concentration range at atmospheric pressure. Experimental densities and viscosities are measured using a vibrating tube densimeter and a glass capillary viscometer, respectively. The relative standard uncertainties estimated in the density and viscosity were 4.8 X 10(-4) and 0.01, respectively. Densities and viscosities of the binary mixtures are compared with the limits established by the diesel fuel standard (EN 590). The binary mixtures of 1-pentanol + 2-methyl-1-butanol, and 2-pentanol + 2-methyl-l-butanol could be considered as alternative substitutes for diesel fuel. Excess molar volume values suggest that these mixtures behave as ideal solutions. Viscosity deviations are negative for all of the mixtures investigated in this study. The Redlich-Kister equation is used to represent the behavior of the excess molar volumes and viscosity deviations as a function of the composition. The Nava-Rios and McAllister equations correlate the kinematic viscosity values with an average absolute percentage deviation of 0.139% and 0.203%, respectively.