Butanol can be obtained from microbial fermentation of cellulose and have the potential of second generation fuel additives. In this paper, viscosity and ultrasonic speed of binary mixture of n-butanol, sec-butanol, isobutanol and tert-butanol + o-xylenes, m-xylene and p-xylene were measured at temperature 308.15 K. Deviation in viscosity and ultrasonic speed were calculated from experimental data and fitted to Redlich-Kister polynomial. The isentropic compressibility and other acoustic properties like available volume and excess intermolecular free length were also calculated. The measured properties were correlated using various empirical relations. The viscosity data were also interpreted in terms of an approach for associated mixtures which yielded meaningful information about intermolecular interactions.