| 摘要 |
PURPOSE:To improve a hydroplaning performance at the time of turning without lowering a hydroplaning performance at the time of beeline travel, by positioning the total width of longitudinal grooves within a fixed range in a sphere where regulation is made with a ground contacting surface circumferentially extending center line as a center. CONSTITUTION:At a pneumatic tire, a tread pattern 11 equipped with longitudinal grooves G extending in a tire circumferential direction and latitudinal grooves g(gm, go) crossing grooves G, is formed at a tread portion. In this instance, the sum of a center longitudinal groove GM groove width WM and two outside longitudinal groove GO, GO groove widths WO, WO at a ground contacting surface S, that is, a total longitudinal groove width WE which is the total length of the groove widths of longitudinal grooves G(=WO+WO+WM) is made to be 10-30% of a ground contacting width W which is the tire axis direction length of the ground contacting surface S. And 70-90% of the total longitudinal groove width WE is positioned at a distance between a ground contacting surface S circumferentially extending center line C and a ground contacting surface S tire axial direction outer edge F, that is, a range A where 30-70% of 1/2 times of the ground contacting width W is separated from the center line. |
