Frequency Calculations

WARNING: This page is about a different car, the 2018 Ford EcoSport. However, it is still accessible from the selected car via links, so may be relevant.

Calculating Tire and Wheel Frequency

For a vibration concern, use the vehicle speed to determine tire/wheel frequency and Revolutions Per Minute (RPM). Calculate the tire and wheel Revolutions Per Minute (RPM) and frequency by carrying out and following:

Measure the diameter of the tire.
Record the speed at which the vibration occurs.
Obtain the corresponding tire and wheel Revolutions Per Minute (RPM) and frequency from the Tire Speed and Frequency Chart.
- If the vehicle speed is not listed, divide the vehicle speed at which the vibration occurs by 16 km/h (10 mph). Multiply that number by the 16 km/h (10 mph) tire Revolutions Per Minute (RPM) listed for that tire diameter in the chart. Then divide that number by 60. For example: a 40 MPH (Miles Per Hour) vibration with 835 mm (33 in) tires. 40 divided by 10 = 4. Multiply 4 by 105 = 420 Revolutions Per Minute (RPM). Divide 420 Revolutions Per Minute (RPM) by 60 seconds = 7 Hertz (Hz) at 40 MPH (Miles Per Hour).