| 摘要 |
<p>To significantly improve performances on ice by optimizing a tread pattern. This pneumatic tire has, in at least a part of a tread portion 1, a block group G B formed by arranging blocks 3 close to each other, the blocks being defined by grooves 2 and being independent of each other, and when a symbol P (mm) stands for a reference pitch length of the blocks in the block group G B , a symbol W (mm) stands for a width of the block group G B , a symbol a (pieces) stands for the number of the blocks 3 existing in a reference zone Z of the block group G B , the reference zone being comparted by the reference pitch length P and the width W, and a symbol N (%) stands for a negative ratio in the reference zone Z, a block number density S, which is the number of the blocks per unit of an actual ground contact area of the block group G B and given by a formula of S = a/{P × W × (1 - N/100)}, is set within a range of not less than 0.003 (pieces/mm 2 ) but not more than 0.04 (pieces/mm 2 ).</p> |
