Pneumatic radial tire for passenger vehicle

A tire-rim assembly formed by assembling a pair of bead portions of a passenger vehicle pneumatic radial tire, having a carcass constituted of plies as radially-disposed carcass cords and provided in a toroidal shape across the pair of bead portions, a belt constituted of one or two belt layers, and at least one belt reinforcing layer as a rubber-coated cord layer extending in a tire circumferential direction, the belt and the belt reinforcing layer being provided on the outer side in a tire radial direction of the carcass, characterized in that:

• provided that SW and OD represent a cross sectional width and an outer diameter of the tire, respectively, SW≥145 (mm),
• SW/OD≤0.26 when 145 (mm)≤SW<165 (mm) and
• SW and OD satisfy a formula shown below when SW≥165 (mm)
• OD≥2.135×SW+282.3;
• provided that each half portion in a tire width direction of a ground contact surface of the tire is divided in the tire width direction into three equal portions including a tire-width-direction center portion, a tire-width-direction intermediate portion and a tire-width-direction outer portion from a tire-width-direction center side, rigidity in the tire circumferential direction of the belt reinforcing layer in a region in the tire width direction thereof corresponding to a tire-width-direction outer side portion is lower than rigidity in the tire circumferential direction of the belt reinforcing layer in a region in the tire width direction thereof corresponding to the tire-width-direction center portion;
• and
• an aspect ratio of the passenger vehicle pneumatic radial tire is greater than or equal to 50 and less than 70,
• wherein SW≥165 (mm) and SW and OD satisfy the following formulae:
• 2.135×SW+282.3≤OD<(1/0.26)×SW,
• the tire-rim assembly is filled only with gas,
• the rim diameter of the tire is greater than or equal to 431.8 mm and less than or equal to 558.8 mm, and
• the outer diameter of the tire is greater than or equal to 638.7 mm and less than or equal to 751.3 mm.

A tire-rim assembly formed by assembling a pair of bead portions of a passenger vehicle pneumatic radial tire, having a carcass constituted of plies as radially-disposed carcass cords and provided in a toroidal shape across the pair of bead portions, a belt constituted of one or two belt layers, and at least one belt reinforcing layer as a rubber-coated cord layer extending in a tire circumferential direction, the belt and the belt reinforcing layer being provided on the outer side in a tire radial direction of the carcass, characterized in that:

• SW and OD satisfy a first condition shown below:
• SW/OD≤0.26;
• and 145 (mm)≤SW<165 (mm), or
• SW and OD satisfy a second condition shown below:
• SW≥165 (mm);
• and OD≥2.135×SW+282.3,
• where SW and OD represent a cross sectional width and an outer diameter of the tire, respectively,
• provided that each half portion in a tire width direction of a ground contact surface of the tire is divided in the tire width direction into three equal portions including a tire-width-direction center portion, a tire-width-direction intermediate portion and a tire-width-direction outer portion from a tire-width-direction center side, rigidity in the tire circumferential direction of the belt reinforcing layer in a region in the tire width direction thereof corresponding to a tire-width-direction outer side portion is different from rigidity in the tire circumferential direction of the belt reinforcing layer in a region in the tire width direction thereof corresponding to the tire-width-direction center portion,
• an aspect ratio of the passenger vehicle pneumatic radial tire is greater than or equal to 50 and less than 70,
• provided that D represents a rim diameter of the tire, SW and D satisfy the following formula
• 0.30<SW/D≤0.52,
• the tire-rim assembly is filled only with gas,
• the rim diameter of the tire is greater than or equal to 431.8 mm and less than or equal to 558.8 mm, and
• the outer diameter of the tire is greater than or equal to 638.7 mm and less than or equal to 751.3 mm.