Speedometer Test -

Repairs to the gearbox, where most speed sensors are located, can cause calibration issues.

Installing tires with a different rolling diameter (e.g., larger or smaller) directly affects speedometer calibration. speedometer test

A traditional, low-tech method involving a measured mile marker on a highway. Driving at a constant 60 mph should take exactly 60 seconds. A faster time indicates the speedometer is reading low, and vice-versa. Repairs to the gearbox, where most speed sensors

Performed by professional mechanics, a "dyno" test places the vehicle on rollers, allowing it to "drive" at high speeds while stationary. The technician records the dashboard speed versus the actual wheel rotation speed to identify discrepancies. Repairs to the gearbox