The invention concerns an impeller (1a, 1b, 1c, 1d, 1e, 1f) of a motor vehicle fan comprising: a cylindrical ring (2) having a center (P), blades (3) extending from the cylindrical ring (2) and toward the center (P), each blade (3) having two radially opposite ends (4, 5), referred to as the blade root end (4) and the blade tip end (5), the blade root end (4) being directed toward the center (P) and the blade tip end (5) being secured to the cylindrical ring (2), characterized in that all the blade root ends (4) are free or linked together by a central hub (20) of reduced diameter.