How to Calibrate an Inaccurate Speedometer?

[DelilahRose]

Speedometer calibration methods vary by vehicle model, so it is recommended to have it performed by professionals at a 4S dealership. The speedometer displays the vehicle's speed in either miles per hour or kilometers per hour, with speed measurement achieved through a speed sensor. The vehicle's speed is closely related to wheel radius and axle structure. There are two main reasons why a car speedometer may display a higher value than the actual speed: safety considerations and calculation errors. China's roads have maximum speed limits based on accident statistics and road conditions to prevent speeding and overtaking. Additionally, onboard speed measurement devices may have delays, so displaying a higher value than the actual speed helps prevent sudden acceleration hazards.