Patent ID: 8381782

Claim:
A heavy duty pneumatic tire comprising: a tread portion provided with tread grooves including at least five longitudinal grooves including a central longitudinal groove extending in a zigzag manner, intersecting a tire equator, two outer longitudinal grooves disposed one on each side of the central longitudinal groove, and two intermediate longitudinal grooves disposed one between each said outer longitudinal groove and the central longitudinal groove, and central lateral grooves extending between the central longitudinal groove and the intermediate longitudinal grooves, intermediate lateral grooves extending between the intermediate longitudinal grooves and the outer longitudinal grooves, and outer lateral grooves extending from the outer longitudinal grooves 2 S to tread ends so as to form a block pattern made up of blocks including central blocks delimited by the central longitudinal groove, the intermediate longitudinal grooves and the central lateral grooves, intermediate blocks delimited by the intermediate longitudinal grooves, the outer longitudinal grooves and the intermediate lateral grooves, and outer blocks delimited by the outer longitudinal grooves, the outer lateral grooves and the tread ends, wherein the total length EC 00 of circumferential components and the total length EL 00 of axial components of edges of the blocks at the tread surface in a new condition when the tread portion is not worn, the total length EC 50 of circumferential components and the total length EL 50 of axial components of edges of the blocks at the tread surface in a 50% wear condition when the tread portion is worn out to 50% of a deepest depth of the tread grooves, and the total length EC 90 of circumferential components and the total length EL 90 of axial components of edges of the blocks at the tread surface in a 90% wear condition when the tread portion is worn out to 90% of said deepest depth satisfy the following six equations: EC 50 >EC 00 (1) EC 90 >EC 00 (2) EL 50>0.5 ×EL 00 (3) EL 90>0.5 ×EL 00 (4) 1.5 <EC 50 /EL 50<2.2 (5) 2.5 <EC 90 /EL 90<3.5 (6).