We have observed that the insertion of trivalent cations into the lattice of Ce0.6Zr0.4O2 solid solution improves the oxygen storage capacity at low temperatures by decreasing the temperature of the reduction in the bulk of the solid solution compared to the undoped sample. The effect depends on the type of dopant and its concentration. Reduction of the solid solution at moderate temperatures is strongly improved upon aging in H-2/Ar independently of the extensive sintering of the sample.