A self-inflating tire (12) is disclosed having a tire cavity (40), first and second sidewalls (32) extending respectively from first and second tire bead regions (34) to a tire tread region, a groove or passageway (60) positioned within the tire (12), and a tube (50) positioned within the groove or passageway (60). The tube (50) has a circular cross-sectional shape and has an outside diameter D. The groove or passageway (60) does not have a circular cross-sectional shape and has a width W and a length L, and wherein D is greater than W.
