Mixtures of dipolar and nonpolar two-centre Lennard-Jones molecules of elongation L = 0.505 are considered. The dipolar molecules differ from the nonpolar ones only by an additional point dipole. NVT molecular dynamics simulations were performed for 100 mixtures and 36 pure fluid state points. From the simulation raw data excess Helmholtz energies were obtained by the lambda-coupling method, which were used to calculate excess Gibbs energies by a thermodynamic expansion. Excess Gibbs energies as functions of composition are now available for three reduced dipole moments mu2/(epsilonsigma3) = 4, 8 and 12, at the reduced temperature k(B)T/epsilon = 1.5390 for one pressure, at k(B)T/epsilon = 2.1546 for two pressures, and at k(B)T/epsilon = 3.0780 for three pressures including here one pressure studied previously. At the highest temperature no liquid/liquid phase separation could be found in the pressure range considered, whereas at medium temperatures phase separation occured for the highest dipole moment mu*2 = 12, and at the lowest temperature demixing was found to occur for the dipole moment mu*2 = 8. The effect of increasing the pressure is to increase the excess Gibbs energy.