Heavy duty tire

A heavy duty tire comprising a carcass extending from a tread part through a sidewall part to a bead core of a bead part and a belt layer arranged outside in a tire radial direction of the carcass and inside of the tread part,

• wherein the belt layer is formed by a belt ply comprising a first belt layer, a second belt layer, and a third belt layer which are laminated in order from inside in the tire radial direction,
• wherein the tread has a plurality of main grooves extending continuously in a tire circumferential direction,
• wherein the tread comprises a cap rubber layer constituting a tread surface and a base rubber layer adjacent to inside in a tire radial direction of the cap rubber layer,
• wherein the cap rubber layer and the base rubber layer are composed of a rubber composition comprising a rubber component,
• wherein the rubber component constituting the cap rubber layer comprises 65 to 90% by mass of an isoprene-based rubber and 10 to 35% by mass of a butadiene rubber,
• wherein the rubber composition constituting the cap rubber layer comprises 45 to 110 parts by mass of silica having a nitrogen adsorption specific surface area (N2SA) of 180 m2/g or more based on 100 parts by mass of the rubber component,
• wherein a ratio of a storage elastic modulus Ec′ of the rubber composition constituting the cap rubber layer at 70° C. is 4.4 to 7.8 MPa,
• wherein a tan δ of the rubber composition constituting the base rubber layer at 70° C. is 0.04 to 0.07,
• wherein an elongation at break of the rubber composition constituting the base rubber layer is 380% or more,
• wherein a ratio of the storage elastic modulus Ec′ of the rubber composition constituting the cap rubber layer at 70° C. to a storage elastic modulus Eb′ of the rubber composition constituting the base rubber layer at 70° C. (Ec′/Eb′) is 1.1 to 1.7, and
• wherein, when, in a tire meridional cross section including a tire rotation axis, a thickness of the cap rubber layer on a normal line extending from an end of a tire rotation axis direction of the third belt layer down to the tread surface is Te, a thickness of the cap rubber layer at a position half a distance from a tire equatorial plane to the end of the tire rotation axis direction of the third belt layer is Tm, and a thickness of the cap rubber layer on the tire equatorial plane is Tc, Te is smaller than Tc, and Te, Tm, and Tc satisfy the following Mathematical expression (3) and (4):
• 0.85≤Tc/Tm≤1.15 (3)
• 1.00<Tm/Te≤1.15 (4).