Pneumatic tire

A pneumatic tire, comprising:

• a plurality of circumferential main grooves extending in a tire circumferential direction;
• and a plurality of land portions partitioned by the circumferential main grooves in a tread portion,
• a first region in the tread portion bordered by a tire equatorial plane being an inner side region, and a second region being an outer side region,
• the land portions respectively having a plurality of sipes extending in a tire width direction, and center land portions in the inner side region and the outer side region being provided with both three-dimensional sipes and two-dimensional sipes, the three-dimensional sipes having a three-dimensional structure portion in a center portion and having a two-dimensional structure portion at both end portions, and the two-dimensional sipes being made up solely of a two-dimensional structure portion,
• a snow traction index STI in the tire circumferential direction throughout an entire tread portion being in a range of 100≤STI,
• a sipe component STI_s_out of the snow traction index STI in the outer side region and a sipe component STI_s_in of the snow traction index STI in the inner side region having a relationship of 2.0≤STI_s_in/STI_s_out,
• a peripheral length ratio PLR_out of a three-dimensional structure portion of sipes in the outer side region and a peripheral length ratio PLR_in of the three-dimensional structure portion of sipes in the inner side region having a relationship of 1.1≤PLR_in / PLR_out, and
• the peripheral length ratio PLR_out of the three-dimensional structure portion of sipes in the outer side region is in a range of 0.4≤PLR_out ≤0.7, and the peripheral length ratio PLR_in of the three-dimensional structure portion of sipes in the inner side region is in a range of 0.6≤PLR_in≤0.8.