Monoply pneumatic run-flat tire with composite ply cord

A pneumatic tire comprising:

• (a) a single carcass ply extending from one bead area to an opposing bead area;
• (b) at least one belt ply disposed radially outward of the carcass ply in a crown portion of the tire;
• and
• (c) at least one insert located adjacent the carcass ply in each of two sidewall portions, the insert providing support for the tire load to enable the tire to operate in underinflated conditions wherein
• the carcass ply is comprised of at least one composite cord, each said cord comprising at least two organic fiber first yarns twisted helically about at least two organic fiber second core yarns, the first yarns and the second yarns having different moduli of elasticity, the first yarns having a modulus of elasticity greater than a modulus of elasticity of the second yarns, the first yarns having a first yarn twist direction, the second yarns twisting about each other in a second opposite direction, the second yarns having the first yarn twist direction, the first yarns wrapping in the second opposite direction about the second yarns previously twisted about each other, and the entire composite cord having a twist in the second opposite direction, the number of high modulus first yarns versus the number of low modulus second yarns being either 2/2, 2/3, or 3/3.