Abstract: The run-flat tire includes thickened load bearing sidewall portions, a belt package plus a cap ply, three pairs of sidewall rubber crescent-shaped reinforcing members, a specially designed bead seat area with a rim seat ply and three carcass layers. The three carcass layers are positioned between the crescent-shaped members in each load bearing sidewall.

Abstract: The weight, space and convenience advantages of a run-flat tire can be substantial. This is especially true for the urban-economy car or family type vehicles which have limited space available for a spare tire and inadequate space for the removed flat tire. These vehicles also have higher comfort requirements that must be addressed. The mini-spare solution to the flat tire problem has very limited performance capabilities. Other solutions include major modifications in the rim and/or the tire, which are not cost effective or compatible with a conversion to standard tires on the same rims.The run-flat tire of this invention includes thickened sidewall portions, a belt package with a cap ply, lower sidewall rubber support portions, a specially designed bead seat area with a rim seat ply and three carcass layers. The classical problems of inflated vs. deflated performance tradeoffs in ride comfort, handling, radial stiffness and endurance of the tire are substantially improved.