Currently, I'm working on an app which should show Gauge value (inHg) of the vehicle using OBD reader. Which values should I use to show the Gauge? Is there any formula?
Gauge pressure (GP) is linked to absolute pressure (AP) by atmospheric pressure as in :
AP = GP + atmos p
Units can be Bar, Pascals, psi, mmH2O, inHg etc
But you can have them selected based on location ie Bar works well in Europe, psi in UK etc