The invention provides carpet fibers prepared from a blend of polymeric components, said fiber exhibiting improved properties, such as improved spinnability and improved fire resistance. The carpet fibers particularly comprise a majority of polytrimethylene terephthalate (PTT) and a minority of polyethylene terephthalate (PET). The invention further provides yarns and carpets prepared from the inventive fibers, said yarns and carpets likewise exhibiting improved properties. The invention also provides methods of improving various physical properties (such as fire resistance, spinnability, and elongation) of a polymeric composition.