The p rho Tx properties for binary mixtures of trans-1,3,3,3-tetrafluoropropene (HFO1234ze(E)) + propane (HC290) were performed in the gaseous phase by a compact single-sinker densimeter. The experimental measurements covered temperatures from (258.146 to 293.353) K, pressures from (0.0989 to 0.8255) MPa, and compositions from (0.1680 to 0.8949) mole fractions of HFO1234ze(E). The standard uncertainties in this work were estimated to be within 5 mK for temperature, 200 Pa for pressure, 0.0003 for compositions and 0.06% for density. A truncated virial equation of state was employed to correlate the present experimental p rho Tx data. Good agreement with the virial equation for the experimental pressures and densities were found with average absolute relative deviations of 0.051% and 0.055%, respectively. In addition, the truncated virial equation with six different combinations of empirical correlating methods for the second and the third virial coefficients were used to predict the experimental densities of HFO1234ze(E), HC290 and their mixtures, where good agreement were also found. (C) 2015 Elsevier B.V. All rights reserved.