I have a new 2020 BMW X3. The speedometer reads about 3 miles per hour faster than actual speed. This is a known problem, confirmed by my BMW dealers service department. Apparently BMW foisted a number of vehicles with mis-calibrated speedometers on an unsuspecting American public. Now refuses to do anything about it since its within spec. Wrong answer. When you know you have a common mode problem with a safety subsystem, which the speedometer is, you fix it. User's recommendation: Complain to BMW if you have one of these mid-calibrated speedometer. If enough new owners complain, maybe they will take the problem seriously.