Pneumatic tire

A pneumatic tire comprising:

• at least four ribs extending in a tire circumferential direction, defined and formed by at least three circumferential grooves extending in the tire circumferential direction in a tread portion thereof,
• at least two of the at least four ribs including one of the at least four ribs disposed on a first side of a tire equatorial plane in a tire width direction and another one of the at least four ribs disposed on a second side thereof, at least three of the at least four ribs protruding to an outer side in a tire radial direction beyond a profile line of a tread surface when viewed in a meridian cross section, the protruding amounts of the at least three of the at least four ribs decreasing in order from the first side towards the second side in the tire width direction,
• a cap tread forming a tread surface of the tread portion is composed from different types of compounds, and a loss tangent tan δ at 60° C. of one of the compounds in a region where the rib has the least protruding amount is smaller than a loss tangent tan δ of another one of the compounds in a region of the rib where the protruding amount is the greatest, the ribs protruding beyond the profile line are provided adjacent to one another interposed by one of the circumferential grooves, and the difference between the protruding amounts of the adjacent ribs is from 0.4 mm to 0.8 mm, both inclusive.