A chassis dynamometer includes at least one roll for engaging the driven wheel of a motor vehicle and a power supplying and/or absorbing unit ("PAU") coupled to the roll. Speed and force sensors are also coupled to the roll for providing signals representative of the roll speed and force supplied to or received from the roll, respectively. Vehicle inertia, road load and parasitic loss signals, representative of the vehicle inertia, the vehicle road load and dynamometer parasitic losses, respectively, are also provided. A processing unit, such as a computer, calculates a velocity error signal based on the above signals, representative of the difference between the desired and actual speed of the vehicle. The processing unit further generates a feed-forward signal in response to the speed and inertia signals, representative of at least a portion, and preferably one hundred percent, of the inertial force signal to be simulated by the PAU. A power controller in response to the feed-forward signal and the velocity error signal controls the PAU.