A tire having an axis of rotation and defining lateral and circumferential directions, the tire comprising: a tread portion extending circumferentially around the tire, said tread portion having at least one tread feature comprising: a pair of sides (106, 206, 406, 506) that are opposed along the lateral direction; a groove (104, 204, 404, 504) extending between the pair of sides, the groove comprising a radially-outer portion fluidly connected with a radially-inner portion, the radially-outer portion of the groove defined by a pair of planar walls extending substantially parallel to each other, and the radially-inner portion of the groove comprising a plurality of voids (114, 214, 414, 514) that are spaced apart along the length of the groove, each void defined by i) a pair of diverging side walls that diverge along the radial direction moving toward the axis of rotation of the tire and ii) a base wall connected between the pair of diverging side walls; characterized in that the diverging sidewalls are planar and the base wall is planar. a tread portion extending circumferentially around the tire, said tread portion having at least one tread feature comprising: a pair of sides (106, 206, 406, 506) that are opposed along the lateral direction; a groove (104, 204, 404, 504) extending between the pair of sides, the groove comprising a radially-outer portion fluidly connected with a radially-inner portion, the radially-outer portion of the groove defined by a pair of planar walls extending substantially parallel to each other, and the radially-inner portion of the groove comprising a plurality of voids (114, 214, 414, 514) that are spaced apart along the length of the groove, each void defined by i) a pair of diverging side walls that diverge along the radial direction moving toward the axis of rotation of the tire and ii) a base wall connected between the pair of diverging side walls; a pair of sides (106, 206, 406, 506) that are opposed along the lateral direction; a groove (104, 204, 404, 504) extending between the pair of sides, the groove comprising a radially-outer portion fluidly connected with a radially-inner portion, the radially-outer portion of the groove defined by a pair of planar walls extending substantially parallel to each other, and the radially-inner portion of the groove comprising a plurality of voids (114, 214, 414, 514) that are spaced apart along the length of the groove, each void defined by i) a pair of diverging side walls that diverge along the radial direction moving toward the axis of rotation of the tire and ii) a base wall connected between the pair of diverging side walls; the radially-outer portion of the groove defined by a pair of planar walls extending substantially parallel to each other, and the radially-inner portion of the groove comprising a plurality of voids (114, 214, 414, 514) that are spaced apart along the length of the groove, each void defined by i) a pair of diverging side walls that diverge along the radial direction moving toward the axis of rotation of the tire and ii) a base wall connected between the pair of diverging side walls; characterized in that the diverging sidewalls are planar and the base wall is planar.