In previous work, a generalized quartic equation of state has been developed and extended to polar fluids. There are forty general regressed coefficients used in the four parameters in the equation of state. Simplification of the quartic equation of state has been done by setting fifteen of those coefficients to zero and obtaining the remaining twenty-five coefficients from regression on the original data base of non-polar and polar fluids. The results of simplification show that the quartic equation of state can achieve similar accuracy with fewer coefficients. The quartic equation of state was tested on thirty-five binary systems and four ternary systems to see the performance of the quartic equation of state on mixtures. The results show that the performance of the quartic equation of state on mixtures is generally comparable to that of the Peng-Robinson equation of state.