How is the mileage calculated?
1 Answers
The principle is actually quite simple: it involves multiplying the tire's rotation count by its circumference. Since the tire's circumference is fixed, knowing the wheel's rotation count allows calculation of the vehicle's mileage and speed. For example, if a tire has a circumference of 1 meter and rotates 1000 times per minute, the car would travel 1000 meters per minute, or 36 kilometers per hour. The main difference between various types of odometers lies in how they obtain the wheel rotation signal. Most vehicles use electronic odometers. The dashboard essentially functions as a display screen, with parameters controlled by the vehicle's computer. The speed sensor transmits the wheel rotation signal to the computer, which calculates a value based on pre-stored programs and displays it on the dashboard, continuously updating as the car moves. There are two methods for the speed sensor to obtain signals: one is from the transmission output shaft, and the other utilizes the ABS wheel speed sensor's signal. Most vehicle dashboards display two types of mileage: one is the total mileage the car has traveled, and the other is a measurable mileage that can be manually reset by the car owner. Next to most digital displays, there's a small button (cylindrical in shape) that can be held down to reset the measurable mileage.
