Chado,
If you haven't already, I suggest you download & print a copy of the instruction manual.
Calibration of the KPH/Fuel is listed on page 36.
This is what it says but the important bits are steps 1-4
Calibrate MPG/Fuel
MENU Vehicle Setup .. Calibration.. Calibrate MPG/Fuel
This calibration is used to fine-tune UltraGauge to accurately measure fuel usage. This calibration is critical, especially for vehicles which use a MAP sensor, diesels and alternative fuels.
For vehicles that use a MAP sensor*, see the menu section on Adaptive Volumetric Efficiency before proceeding.
Prior to this calibration, consider performing the distance calibration. See the section: Calibrate Distance
Calibration can not be performed if less than 4 liters or 1 gallon have been used. It is best to use a full tank or more.
The gauges that depend on fuel usage will not be accurate until this calibration is complete. To perform calibration, please follow these steps.
1.
Fill up the fuel tank. Once filled, press and hold the UP key to cause UltraGauge to recognize the fill-up
2.
Zero the Average MPG. MENU Gauge/Page Menu .. Zero Ave MPG, G/H.
3.
At the next fuel fill-up, note the number of gallons/liters used (pumped). Select MENU Vehicle Setup.. Calibration.. Calibrate MPG/Fuel and enter the fuel used. Press MENU when complete to set and save the calibration. Use the same fuel station and pump for best results. Alternatively, record and add the actually gallons used over several fill-ups to improve accuracy.
4.
The Calibration factor will be displayed at the bottom of the screen.
I hope it's not subject to copyright.
If you give this a go & get stuck, let me know the bit that does not make sense & I will see if I can help.