TIRE TREAD RUBBER COMPOSITION AND TIRE USING THE SAME

In order to improve steering stability at the time of turning while ensuring good fuel efficiency, there is provided a tire tread rubber composition including a rubber component containing styrene-butadiene-based rubber and isoprene-based rubber, wherein the hardness Hs at 23 °C is 55 or greater and 62 or less, and the hardness Hs at 23 °C and the loss tangent tan δ at 35 °C satisfy the following formula: 0.240 ≤ tan δ/Hs × 100 ≤ 0.320. There is also provided a tire having a tread composed of this tire tread rubber composition.