Heavy duty pneumatic tire

A heavy duty pneumatic tire (1) comprises a tread portion (2) provided with circumferentially continuous main grooves (3) and lateral grooves (4) to form blocks (6) in circumferential rows (7). The main grooves include a pair of shoulder main grooves (12) disposed one on each side of the tire equator so that the center line thereof is at a distance D1 of 0.30 to 0.65 times one half of the tread width TW from the tire equator. The blocks include crown blocks (23) disposed in a tread crown region (Cr) between the shoulder main grooves (12), and shoulder blocks (24) disposed in shoulder regions (Sh) axially outside the shoulder main grooves (12). Each of the crown blocks and shoulder blocks is provided with at least one axially extending sipe (26). The following equation is satisfied: (SScr+SBcr)/(SSsh+SBsh) ‰¥ 1.05. SScr is a total sum of axial lengths (L1) of the sipes of all of the crown blocks (23). SBcr is a total sum of axial lengths (L2) of lateral edges (23e) of the ground contacting faces (2t) of all of the crown blocks (23), wherein each of the lateral edges is one of two circumferentially-opposite lateral edges of the ground contacting face of one of the crown blocks. SSsh is a total sum of axial lengths (L3) of the sipes (26) of all of the shoulder blocks (24). SBsh: a total sum of axial lengths (L4) of lateral edges (24e) of the ground contacting faces (2t) of all of the shoulder blocks (24), wherein each of the lateral edges is one of two circumferentially-opposite lateral edges of the ground contacting face of one of the shoulder blocks.