A tire (10) comprises a crown (12) comprising a tread (20), a crown reinforcement (14), two sidewalls (22), two beads (24), with each sidewall (22) connecting each bead (24) to the crown (12), the crown reinforcement (14) extending into the crown (12). The tire (10) comprises a radial carcass reinforcement (32) anchored in each of the beads (24) and extending into the sidewalls (22), and the crown reinforcement (14) is radially inserted between the carcass reinforcement (32) and the tread (20). The tire (10) has a sidewall height that is greater than or equal to 110 mm and a load index that is greater than or equal to 94. The carcass reinforcement (32) comprises a single carcass ply (34) comprising at least one reinforcer element comprising an assembly formed by: a multifilament strand made of aromatic polyamide or aromatic co-polyamide; and a multifilament strand made of polyester.

A multi-strand cord (50) comprises an internal layer (CI) of the cord made up of K=1 three-layer (C1, C2, C3) internal strand (TI), with the internal layer (C1) being made up of Q internal metallic threads (F1), the intermediate layer (C2) being made up of M intermediate metallic threads (F2) and the external layer (C3) being made up of N external metallic threads (F3), and an external layer (CE) of the cord made up of L>1 three-layer (C1, C2, C3) external strands (TE) wound around the internal layer (CI) of the cord, with the internal layer (C1) being made up of Q internal metallic threads (F1), the intermediate layer (C2) being made up of M intermediate metallic threads (F2) and the external layer (C3) being made up of N external metallic threads (F3). The cord (50) has an endurance criterion SL40 000 MPa.Math.mm with $SL=\max \left(\frac{{}_{\mathrm{bending}\_\mathrm{CI}}}{\mathrm{Cp}};\frac{{}_{\mathrm{bending}\_\mathrm{CE}}}{C_r\mathrm{Cp}}\right);$
and a size criterion Ec0.46 with Ec=Sc/Se.

The present invention relates to an eco-friendly tire cord and a tire using the eco-friendly tire cord, in which use of a recycled polyethylene terephthalate (PET) fiber reduces environmental load and also provides physical properties equivalent to or better than those of a tire cord that is produced by application of a virgin PET fiber and particularly, excellent heat resistance equivalent to or better than that of a tire cord produced by application of a virgin PET.