Tire design based on first principles of structural engineering

A tire comprising a pair of substantially annular beads (12), at least one carcass ply (16) wrapped around said beads, tread (22) disposed over said carcass ply in a crown area of said tire, belt reinforcement (20) interposed between said tread and said carcass ply, and sidewalls (18) disposed between said tread (22) and said beads (12), each of said sidewalls in the tire having a lower sidewall region (18b), a mid-sidewall region (18c), and an upper sidewall region (18a), and a wedge (21) bridging each of said sidewalls and said tread (22), said tire (10) having said lower sidewall region (18b) which is integrally connected with a bead area (12a) of said tire and is stiffened with an apex (17), said lower sidewall (18b) being connected to said mid-sidewall (18c) having less stiffness than said lower sidewall, and said upper sidewall (18a) having a geometry and a low flexural stiffness such that it acts like a flexible coil connected to said mid-sidewall (18c) and providing a non-coupling bridge between the tread (22) at the crown of the tire and the mid-sidewall (18c), characterized in that said belt reinforcement (20) has a lateral stiffness equivalent to a belt reinforcement having two steel belts wherein each belt has 7.9 to 9.4 ends per centimeter (e.p.c.) steel cord reinforcement having a diameter of 0.042 cm at an angle of 21°, said apex having a length of 25% to 45% of the section height of the tire and a modulus of 4760 to 6160 Npscm, and said wedge (21) having a modulus of 396 to 594 Npscm bridging said sidewall and tread with a portion contiguous with said belts (20) comprising 37% to 43% of the tread width.