A pneumatic radial ply tire includes a pair of beads, a single carcass ply, a tread, and a pair of sidewalls. The pair of beads each has an associated chaffer. The single carcass ply is folded about each bead so as to define a main body portion and a turnup portion associated with each bead. The tread is disposed radially outward from the single carcass ply. The tread has shoulder portions disposed at axial outer edges of the tread. The pair of sidewalls extends radially outward from each chaffer to a location adjacent each shoulder portion. Each sidewall is disposed axially outward of the single carcass ply. Each sidewall includes a first outer layer extending from the chaffer to the shoulder portion and a second inner layer extending from the chaffer to the shoulder portion. The second inner layer is disposed entirely between the single carcass ply and first outer layer. The second inner layer comprises a foamed structure of a rubber composition having a density ranging from 0.1 to 1.0 g/cm3.