A pneumatic radial tire has a carcass composed of radially inner and outer carcass
plies. A complex elastic modulus E*1 of the topping rubber of the inner carcass
ply is different from a complex elastic modulus E*2 of the topping rubber of the
outer carcass ply, and a ratio E*1/E*2 is 0.95 or lower or 1.05 or higher.
