Board Thread:General Discussion/@comment-26251020-20150416160040/@comment-69.255.244.73-20150517210838

In terms of the actual speed issue, I would say even the speed indicated by real cars are not accurate. If you go 90mph indicated speed and get a speeding ticket, the police probably will read you speed at only 86 or 87. The reason is indicated speed comes form instantaneous angular velocity at the wheel times the perimeter of the wheel. Because of this, it will be inaccurate since 1, Perimeter of the wheel may not be accurate due to factors such as incorrect tire pressure and 2, Tire is not always in perfect contact with the road, any slight wheel spin will result in an inaccurate speed indication. Of course, the fast you go, the more likely you will have wheel spin and the less accurate you indicated speed will be.