Abstract: Testing apparatus for speedometers is disclosed including variable speed control driving means coupled to a flexible drive connection assembly that is adapted for connection with the speedometer. The drive connection assembly includes impulse generating means connected with a digital indicator for indicating the rotational rate of the cable assembly and for providing comparative readings of the indicator and the instrument being tested. The flexible drive assembly is adapted for connection with the flexible drive or the gear box coupling of the speedometer for checking the drive ratio upon rotation of the vehicle traction wheels when moving the vehicle a predetermined distance to determine the number of turns per unit of distance of the speedometer drive cable.