A tire assembly includes a tire, sidewalls, and a sidewall groove. The tire has a pneumatic cavity. The sidewall has at least one bending region operatively bending when radially within a rolling tire footprint of the tire. The sidewall groove is defined by groove sidewalls positioned within the bending region of the tire sidewall. The sidewall groove deforms segment by segment between a non-deformed state and a deformed, constricted state in response to the bending of the sidewall bending region when radially within the rolling tire footprint. An air passageway is defined by the sidewall groove and a cover strip. The air passageway resiliently deforms segment by segment between an expanded condition and an at least partially collapsed condition in response to respective segment by segment deformation of the sidewall groove when radially within the rolling tire footprint.