Abstract: Provided is a pneumatic tire capable of improving fuel efficiency, handling stability, and durability in a balanced manner. The present invention relates to a pneumatic tire, comprising a tread that includes a cap layer and a base layer, the cap layer and the base layer satisfying relationships represented by the following formulas (1) to (3): 50/50?Vc/Vb?90/10??(1) wherein Vc is the volume of the cap layer and Vb is the volume of the base layer, 0.65?E*c/E*b<1.00??(2), and 1.30?(tan ?c/E*c)/(tan ?b/E*b)<2.40??(3) wherein E*c and tan ?c are the complex modulus and the loss tangent, respectively, of the cap layer at 30° C., and E*b and tan ?b are the complex modulus and the loss tangent, respectively, of the base layer at 30° C.

Abstract: Provided is a pneumatic tire capable of improving fuel efficiency, handling stability, and durability in a balanced manner. The present invention relates to a pneumatic tire, comprising a tread that includes a cap layer and a base layer, the cap layer and the base layer satisfying relationships represented by the following formulas (1) to (3): 50/50?Vc/Vb?90/10??(1) wherein Vc is the volume of the cap layer and Vb is the volume of the base layer, 0.65?E*c/E*b<1.00??(2), and 1.30?(tan ?c/E*c)/(tan ?b/E*b)<2.40??(3) wherein E*c and tan ?c are the complex modulus and the loss tangent, respectively, of the cap layer at 30° C., and E*b and tan ?b are the complex modulus and the loss tangent, respectively, of the base layer at 30° C.

Abstract: The rubber composites for tire treads include silica; carbon black; and oil constituents, wherein a ratio (A index) of silica contents, carbon black contents, and oil constituents contents is represented by A index=silica contents/(carbon black contents+silica contents+oil constituents contents)?0.8; and a ratio (B index) of a complex elastic modulus E* at 30° C. and a loss tangent tan ? at 60° C. is represented by B index=E*/tan ??120.

Abstract: There are provided the tire motor 5 for increasing or decreasing the tire rotational frequency Nt while the tire 3 is being rotated around the tire rotational shaft 1, the rotational frequency measuring means 6 for measuring the tire rotational frequency Nt, the drum motor 11 for rotating the test drum 12 around the drum rotational shaft 14 at the constant drum speed Vd, the speed meter 15 for measuring the drum speed Vd, the load applying means 4 for pushing the tire 3 against the test drum 12 with the tire load Fz, the radial force load cell 2 for measuring the tire load Fz, the tangential force load cell 2 for measuring the tangential force Fx that is exerted on the tire 3, and the recording means for recording the measurement result of each of the drum speed Vd, the tire rotational frequency Nt, the tangential force Fx and the tire load Fz in association with every measurement time point during increasing or decreasing the tire rotational frequency.

Abstract: The rubber composites for tire treads include silica; carbon black; and oil constituents, wherein a ratio (A index) of silica contents, carbon black contents, and oil constituents contents is found by: A index=silica contents/(carbon black contents+silica contents+oil constituents contents)?0.8??relational expression (1); and a ratio (B index) of a complex elastic modulus E* at 30° C. and a loss tangent tan ? at 60° C. is found by: B index=E*/tan ??120??relational expression (2).

Abstract: There are provided the tire motor 5 for increasing or decreasing the tire rotational frequency Nt while the tire 3 is being rotated around the tire rotational shaft 1, the rotational frequency measuring means 6 for measuring the tire rotational frequency Nt, the drum motor 11 for rotating the test drum 12 around the drum rotational shaft 14 at the constant drum speed Vd, the speed meter 15 for measuring the drum speed Vd, the load applying means 4 for pushing the tire 3 against the test drum 12 with the tire load Fz, the radial force load cell 2 for measuring the tire load Fz, the tangential force load cell 2 for measuring the tangential force Fx that is exerted on the tire 3, and the recording means for recording the measurement result of each of the drum speed Vd, the tire rotational frequency Nt, the tangential force Fx and the tire load Fz in association with every measurement time point during increasing or decreasing the tire rotational frequency.