This work reports physical property measurements of binary mixtures of butylbenzene with n-decane, n-dodecane, n-tetradecane, n-hexadecane, or n-heptadecane. Densities and viscosities Were measured at temperatures from (293.15 to 373.15) K, and speeds of sound were measured at temperatures from (293.15 to 333.15) K, except for those of n-heptadecane, which were measured starting at 303.15 K. Densities increased with increasing mole fraction of 'butylbenzene. Excess molar volumes were positive and increased with increasing alkane chain length, except for those,of heptadecane which were similar to those Of n-hexadecane. Analysis of excess molar volumes using the Prigogine-Flory-Patterson model showed that the interaction term contributed more to excess molar volume than the free volume or P* term. As the mole fraction of butylbenzene increased, speeds of sound increased for n-decane and n-dodecane mixtures but decreased for other alkane mixtures to values below those of both pure components before increasing again. Viscosities decreased as the mole fraction of butylbenzene increased,except for those of some n-decane mixtures, which were below those of butylbenzene and n-decane.,Visoosity mole fraction data were fit using the three body McAllister model. Bulk moduli and surface tension increased, with increasing mole fraction of butylbenzene, and flash points fell between those of the individual components. These mixtures can be used as surrogates for petroleum-based fuels.