Abstract: Provided is a pneumatic radial tire for a passenger vehicle, having a carcass constituted of plies as radially-disposed cords and toroidally provided across a pair of bead portions, and including: a belt constituted of one or more belt layers; and a tread, which are disposed in this order on the outside in the radial direction of the carcass, in which: a section width SW and an outer diameter OD of the tire have a ratio of SW/OD?0.26 when SW<165 (mm), and SW and OD satisfy a relationship formula OD?2.035×SW+282.

Abstract: Provided is a pneumatic radial tire for a passenger vehicle, including: a carcass constituted of plies as radially-disposed cords and toroidally provided across a pair of bead portions; and a tread, in which: the tread surface has one or more grooves formed thereon; the grooves each have a groove width of 3 mm or less; and a section width SW to an outer diameter OD of the tire have a ratio of SW/OD?0.26 when SW<165 (mm), and SW and OD satisfy a relationship formula OD?2.035×SW+282.3 when SW?165 (mm).

Abstract: Provided is a pneumatic radial tire for a passenger vehicle, having a carcass, and including a belt and a tread disposed on the outside of the carcass, in which: a section width SW and an outer diameter OD of the tire have a ratio of SW/OD?0.26 when SW<165 (mm), and SW and OD satisfy a relationship formula OD?2.035×SW+282.3 when SW?165 (mm); and provided that V1 represents a volume of rubber lying inside than the both ends of a maximum-width belt layer having a maximum width among the belt layers while lying outside than the reinforcing member which is the outermost layer of the belt layers at the center position in the tire width direction, and that V2 represents a total volume of all the grooves formed in a surface of the tread, V1 and V2 has a ratio V2/V1?20%.