Pneumatic tire and crosslinked rubber composition

A pneumatic tire comprising:

• bead cores provided on a pair of right and left bead portions, respectively;
• a carcass ply extending from a crown portion to the both bead portions through both side wall portions and moored to the bead cores;
• an inner liner disposed at an inner side than the carcass ply in a direction of a tire diameter;
• and
• a tread disposed at an outer side than the carcass ply in a direction of a tire diameter and having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a ratio of 40% by mass or more of a component having a weight-average molecular weight of not less than 1,000,000 in a molecular weight distribution measured by gel permeation chromatography,
• wherein the low density region is a region having a density of 0.1 to 0.8 time the density of a crosslinked rubber composition before the elongation, and
• wherein the void portion is a region having a density of 0 to 0.1 time the density of a crosslinked rubber composition before the elongation,
• wherein the crosslinked rubber composition comprises a rubber component comprising two kinds of styrene-butadiene rubber, and butadiene rubber.