Abstract: Apparatus for dynamometer testing of motor vehicles comprising load absorbing means in the form of a hydrostatic pump assembly which has an input shaft adapted to have a flexurally rigid engagement with a driven vehicle shaft using a rigid coupling. The coupling is mounted on an end portion of the pump input shaft which projects in one direction from a holder that supports the pump assembly. The pump assembly is mounted for limited rotational movement relative to the holder and projects in cantilever fashion in the other direction from the holder. A ground engaging support comprising support wheels is secured to the holder. A strain gauge assembly is connected between the pump assembly and the holder and serves to measure the torque applied to the holder by the pump assembly.