A dual-chamber pneumatic tire having two separate concentric annular air chambers. The outermost air chamber, disposed behind the tire tread normally in contact with the ground has a relatively small volume, is toroidal and substantially elliptical in cross-section and is inflated at a higher pressure than the innermost chamber disposed in the remaining volume of the tire. The two chambers are separated by an elastically deformable, collapsible partition wall or diaphragm which is integrally attached to the interior tread surface near the sidewalls or which is, alternatively, made removable. The low pressure innermost chamber is inflated by means of a conventional air valve or by a regulator valve between the innermost chamber and the outermost chamber, while the outermost chamber is inflated by means of an air valve connected to the wall or diaphragm by means of flexible hose, or, alternatively by a valve disposed at the base of the tire sidewalls. The structure of the invention is particularly adapted to tubeless tires.