Pneumatic tire including protrusion dividing groove space of main groove having groove width narrowed during inflation

The present invention relates to a pneumatic tire provided with a plurality of main grooves extended in a tire circumferential direction on the tread surface. More particularly, the present invention relates to a pneumatic tire capable of controlling uneven wear occurring in the vicinity of the main grooves. Disclosed is a pneumatic tire effectively controlling uneven wear occurring in the vicinity of a main groove even if a groove width of the main groove is narrowed due to change in tread radius during inflation. In the pneumatic tire, with regard to the main groove having its groove width narrowed during inflation among a plurality of main grooves provided on a tread surface, both groove walls are inclined so that the groove width becomes wider toward the groove bottom, and a protrusion dividing the groove space in the tire width direction is provided at the groove bottom.