To improve durability performance and rolling resistance performance in a well-balanced manner. It is a tire for heavy loads including a carcass ply (6A). A sidewall rubber (3G) includes an inside rubber part (15) on the carcass (6) side, and an outside rubber part (16) disposed on the outside thereof and forming a tire outer surface. The inside rubber part (15) has a loss tangent tan δ1 less than the outside rubber part (16), and their difference is 0.010 to 0.035. The inside rubber part (15) has a complex elastic modulus less than the outside rubber part (16), their difference is 0.5 to 1.4 (MPa). The outer end (15s) in the tire radial direction of the inside rubber part (15) contacts with the outer surface (2h) in the tire axial direction of the tread rubber (2G), and the inner end (15u) in the tire radial direction is disposed radially inside the outer end (6e) in the tire radial direction of the turned up portion (6b) of the carcass ply (6A).

In a tire 2, each of sidewalls 6 includes a first layer 36 disposed axially outward of a corresponding one of beads 8, and a second layer 38 extending outward from the first layer 36 in a radial direction. When Pc represents a position of an axially outer end of an interface between a carcass 10 and the sidewall 6, an outer end 40 of the first layer 36 is disposed radially inward of the position Pc. A hardness H1 of the first layer 36 is greater than a hardness H2 of the second layer 38. A ratio (H2/H1) of the hardness H2 to the hardness H1 is preferably not less than 0.70 and preferably not greater than 0.95.

A radial tire (10) for a heavy vehicle of construction plant type, and more particularly, the sidewalls thereof (20), arranged to minimize the temperature of the tire while guaranteeing its electrical conductivity. The tread (30) comprises two tread wings (31) and a central portion (32). The bead layer (71), the elastomeric coating compound of the carcass layer (50), the second sidewall layer (22) and the tread wing (31) constitute a preferential conductive pathway of the electric charges between the rim and the ground when the tire is mounted on its rim and flattened on the ground.

A pneumatic tire includes a pair of bead cores; a pair of bead fillers that are connected to the pair of bead cores; a carcass ply that is suspended between the pair of bead cores; a side wall rubber that is arranged on a tire-outer-surface-side of the carcass ply and constitutes a tire outer surface; a chafer layer that is turned from a tire-inner-surface-side to the tire-outer-surface-side around the bead cores and the bead fillers and rolled up on an outer surface of the carcass ply; and a pair of support rubbers that are located between the side wall rubber and the carcass ply and arranged so as to hold a rolled-up end of the chafer layer from both sides in a tire width direction. A modulus values of the pair of support rubbers are higher than a modulus value of the side wall rubber.

Provided is a pneumatic tire with which the same driving safety as prior arts can be ensured and an improvement in fuel efficiency performance and durability performance is achieved. In this pneumatic tire, the tire radial direction outside end section of a chafer is disposed on the tire surface part, the loss tangent tan δ70° C.-SW of a side wall, the loss tangent tan δ70° C.-C of the chafer, complex elastic modulus E*70° C.-SW of the side wall, and the complex elastic modulus E*70° C.-C of the chafer under the condition of 70° C., an elongation of 1%, and a frequency of 10 Hz, and the loss tangent tan δ150° C.-SW of the side wall, and the loss tangent tan δ150° C.-C of the chafer measured under the condition of 150° C., an elongation of 1%, a frequency of 10 Hz satisfy the following expression. tan δ70° C.-SW+tan δ70° C.-C≤0.25|tan δ70° C.-SW−tan δ70° C.-C|≤0.07 E*70° C.-C−E*70° C.-SW≤6.5 MPa tan δ150° C.-SW+tan δ150° C.-C≤0.20

A heavy duty pneumatic tire 1 has provided in a buttress region 10 thereof a protrusion 11 extending in the tire circumferential direction. In a tire meridian cross-section, the maximum protrusion height h.sub.max of the protrusion 11 from an imaginary buttress surface J is 3.0 mm or greater and is in the range of 0.025-0.050 times a half tread width Wt. The cross-sectional area Sa of the protrusion 11 protruding from the imaginary buttress surface J is 20 mm.sup.2 or greater.

A pneumatic tire includes a pair of bead cores; a pair of bead fillers; a carcass ply; a side wall rubber; a chafer layer that is rolled up on an outer surface of the carcass ply; and a pair of support rubbers that is located between the side wall rubber and the carcass ply and arranged such that a rolled-up end of the chafer layer is sandwiched from both sides in a tire width direction. The pair of support rubbers includes a tape rubber located inside in the tire width direction and a rear pad rubber located outside in the tire width direction. A modulus value of the tape rubber is higher than a modulus value of the side wall rubber. A modulus value of the rear pad rubber is higher than the modulus value of the tape rubber.

Provided is a tire structure technology with which sufficient reading performance can be maintained even when a tire having an electronic component provided therein is caused to drive under high speed and severe handling. A pneumatic tire in which an electronic component is provided farther outward in a tire axial direction than a carcass, and in which the tan δ(1).sub.50° C. and tan δ(1).sub.150° C. of a first rubber member, and the tan δ(2).sub.50° C. and tan δ(2).sub.150° C. of a second rubber member, satisfy the following formula, where the first rubber member is a tire rubber member that has the greatest E* at 50° C. among tire rubber members positioned outward from the electronic component in the tire axial direction, and the second rubber member is a tire rubber member that has the greatest E* at 50° C. among tire rubber members positioned inward from the electronic component in the tire axial direction.
(tan δ(1).sub.50° C.+tan δ(2).sub.50° C.)−(tan δ(1).sub.150° C.+tan δ(2).sub.150° C.)≤0.08

A pneumatic tire having a side portion and a clinch portion, wherein: in a meridian cross section, the distance from a bead baseline to the outside portion in the width direction of the clinch portion is greater than the distance to the inside portion in the width direction; the E*.sub.S of the side portion, as measured at 70° C., a frequency of 10 Hz, an initial distortion of 5%, and a distortion rate of 1%, is less than the E*.sub.C of the clinch portion; and, formulas (1) and (2) are satisfied:

1600≤(Dt.sup.2×π/4)/Wt≤2827.4  (1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (2)

where Wt is the cross-sectional width of the tire installed on a standardized rim and filled with air to an internal pressure of 250 kPa, Dt is the outer diameter, and V is the volume of the tire.

A pneumatic tire is provided which has sufficiently reduced rolling resistance during high-speed running and which has excellent durability. The pneumatic tire has a bead portion, carcass and tread, wherein: a bead-reinforcing layer that reinforces the bead portion from outside of the carcass is provided outside of the carcass in the tire axis direction; and the pneumatic tire satisfies (formula 1) and (formula 2) below, where Wt (mm) is the cross-sectional width of the tire when the tire installed on a standardized rim and the internal pressure is 250 kPa, Dt (mm) is the outer diameter, and the virtual volume V (mm.sup.3) is the volume of the space occupied by the tire.

1600≤(Dt.sup.2×π/4)/Wt≤2827.4  (formula 1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (formula 2)