How to Calibrate the Speedometer?

[IanLee]

Speedometer calibration varies by vehicle model and the adjustment process is relatively complex, so it is recommended to visit a professional 4S shop for technician-assisted calibration. Below is relevant information about speedometers: 1. Working Principle: Vehicle speed measurement is achieved through speed sensors, where the car's travel speed is intrinsically linked to wheel radius and axle structure. Since most automotive components contain iron elements, Hall sensors installed at corresponding positions detect magnetic flux changes. The sensor output continuously varies with axle rotation during driving, with the final speed displayed via a needle gauge on the dashboard speedometer. 2. Reasons for Speedometer Inaccuracy: There are two primary reasons why a car speedometer displays higher values than actual speed: safety considerations and computational errors during measurement.