An electric wire conductor for use in automobiles made by twisting together a plurality of strands. Each of the strands has a surface layer made of copper or a copper alloy and a core made of steel containing 0.05-0.85 percent of carbon and other elements such as Si, Mn, Ni, Cr, Mo, Nb, V, B, Be, Al, or Ti and P, S and Cu. Each strand has a tensile strength of 80-160 kgf/mm.sup.2 before being twisted and a conductivity of 25% IACS or more. The conductor has a total sectional area of 0.05-0.30 mm.sup.2, a breaking load of more than 6 kgf, and an elongation at break not less than 2%.