a hub cap for a vehicular wheel . the hub cap includes a body portion and a wheel coupling portion , both made from a non - metallic material . the wheel coupling portion has circumferentially - spaced lug nut engaging members that are axially alignable with lug nuts extending from the wheel . the lug nut engaging members form a substantially arcuate shape , and are resiliently biased so that upon placement of the hub cap onto a wheel , the lug nuts push the lug nut engaging members in a radial direction . continued contact between the lug nuts and their corresponding engaging members promotes secure connection between the hub cap and wheel . in one embodiment , the body portion and wheel engaging portion is formed from two separate pieces that are subsequently joined , while in another , they are formed from a single unitary structure to define a one - piece construction .