It is well-known that the mesomorphic range as well as the physical properties of low molecular weight mesogens can be tuned by mixing different types of monomers. We show here that a similar tuning can be achieved for side-chain liquid crystalline polymers by incorporating two different types of side groups in the backbone in different ratios. The transition temperatures of these terpolymers show a linear dependence on the ratio of the two mesogenic side groups, while their spontaneous polarization shows nonmonotonic dependence. Also, the spontaneous polarization of the terpolymers shows an unusual (linear) temperature dependence throughout the smectic C-* phase.