Pneumatic tire

A pneumatic tire, comprising:

• an indicator indicating a designated vehicle inner/outer side orientation for mounting the pneumatic tire on a vehicle;
• a reinforcing rubber layer disposed in sidewall portions on both sides in a tire lateral direction, the reinforcing rubber layer having a substantially crescent shaped meridian cross-section;
• wherein
• when the tire is mounted on a regular rim, has an internal pressure of 0 kPa, and is in an unloaded state,
• a radius of curvature ROout with an arc joining intersections of first, second and third straight lines with a tire external contour on the vehicle outer side, and a radius of curvature RPout with an arc joining intersections of the first, second and third straight lines with a carcass layer on the vehicle outer side have a relationship such that, on the vehicle outer side, the radius of curvature RPout of the carcass layer is large with respect to the radius of curvature ROout of the tire external contour,
• a radius of curvature ROin with an arc joining intersections of first, second and third straight lines with a tire external contour on the vehicle inner side, and a radius of curvature RPin with an arc joining intersections of the first, second and third straight lines with the carcass layer on the vehicle inner side have a relationship such that, on the vehicle inner side, the radius of curvature RPin of the carcass layer is small with respect to the radius of curvature ROin of the tire external contour, where
• the first straight lines on the vehicle inner side and on the vehicle outer side are straight lines orthogonal to a tire equatorial plane at a tire maximum width portion when viewed in a meridian cross section,
• the second straight lines on the vehicle inner side and on the vehicle outer side are straight lines from an intersection of the first straight lines and the tire equatorial plane inclined by 10° outward in a tire radial direction with respect to the first straight lines,
• the third straight lines on the vehicle inner side and on the vehicle outer side are straight lines from the intersection of the first straight lines and the tire equatorial plane inclined by 10° inward in the tire radial direction with respect to the first straight lines, and
• the tire external contour joining the intersections of first, second and third straight lines with the tire external contour on the vehicle inner side is a single arc, and the tire external contour joining the intersections of first, second and third straight lines with the tire external contour on the vehicle outer side is a single arc.