UltraGauge Tyre Size Calibration

How to calibrate distance using the GPS method

This distance calibration method is based on using GPS speed. GPS speed is most accurate when driving in a straight line at a constant speed.

Step 1: Adding a speed gauge to the screen (ie: On page 1 of the UltraGauge)

  • Press the menu button and then access Gauge/Page Menu – Select Gauge/Page – Select Gauges – Page 1 Gauges
  • Use the up and down keys to navigate to the KPH gauge
  • Press Menu, this will cause the cursor to blink
  • Press up and down until the number 1 is next to the KPH gauge
  • Press Menu again to lock the gauge into page 1, position 1
  • Leave the menu by pressing back etc
  • The UltraGauge should now be displaying the KPH gauge on page 1, position 1 (top left hand corner of the screen)

Step 2: Take you calculator and GPS speed device (ie: iPhone) to your car and head to a stretch of road, preferably a long straight stretch of road

Step 3: While driving at a constant speed for around 30 seconds, note the speed reading output on both the GPS speed device (ie: iPhone) and the readout on the UltraGauge. The readings could be different.

Step 4: Find a safe place to pull over and park. With your calculator complete the following, GPS speed divided by UltraGauge speed

Step 5: Adjust the ‘Distance Cal’ factor in your UltraGauge

  • Navigate to Menu – Vehicle Setup – Calibration – Calibrate Distance
  • Note the distance value shown by the UltraGauge and on the calculator multiply this by the factor found in step 4
  • Press Menu and then press up or down to adjust the distance value to the calculated value
  • Press Menu to store the updated distance value. The UltraGauge now shows the Disatance cal value
  • Leave the Menu by selecting back etc

Step 6: To check the values are correct please drive along and check once again the GPS speed device value versus that of the UltraGauge output speed

Step 7: Make fine adjustments as required by re-completing the above steps to correct UltraGauge speed output value