A pneumatic tire has a crown-reinforcing insert which extends from under the tread substantially, such as at least one-third of the sidewall height, into the sidewall of the tire. Apexes extend from the beads substantially, such as at least one-third of the sidewall height, into the sidewall of the tire, thereby effecting a substantial, such as at least one-third of the sidewall height, "overlap" between end portions of the crown-reinforcing insert and the apexes. Additionally, at least one belt extends from under the tread substantially into the sidewall, and the turn-ups of at least some of the plies extend quite high, such as at least one-third of the sidewall height, into the sidewall. This combination of features yields superior runflat performance.