Hello I'm Chris a Certified Engine/Transmission Specialist.
Thanks for asking your question. I am eager to get your vehicle back up and running correct, I am here to help you out for a small fee far less than a dealership and easier on the wallet, so if this information is of aid PLEASE PRESS ACCEPT and help me out financially by paying the small fee. Please reply if further discussion is needed.
Yes your dealer can drive your vehicle beside another and compare the speeds and then perform a speedometer calibration update using the scan tool.
Ford Technician
Ford trained Tech. Trans, X-fer Case, Steering & Suspension & Brakes, Engine, Electrical