[DavieGravy]

Thanks for the response Mr. Mummert. I've been under the impression that the drums spin freely with the wheels. So it's as if the car is being driven normally. I could be mistaken about this though. I was just a bit concerned to hear it might be a detrimental thing, considering I've had this test done before and will be required to have it again soon. Perhaps the dyno systems vary from state to state.