To provide for accurate testing of the performance of automotive vehicles on test stands in which the wheels of the vehicle are in engagement with inertia rollers, the inertia rollers being accelerated through the vehicle wheels by the vehicle engine, and the torque measured, and then decelerated by disconnecting of engine driving power and coasting torque measured, operating parameters related to speed and rate of change of speed are sensed and a speed signal is provided, tractive effort is sensed and a traction signal provided, and the signals are combined to provide an output representative of engine performance, the combined signals being further modified by the output of a correction stage which introduces correction signals such as pressure, ambient temperature, presence or absence of automatic transmission, or the like; the apparatus further comprises selectable switches, for example a speed selector switch, so that measurements can be taken with respect to predetermined design speeds to test performance of the vehicle, or an engine, with respect to such a predetermined speed.
展开▼
