Sorry, wrong choice of words there. If the conditions during test were at the calibrated ideals, I should be getting more at the wheels.
Air pressure was down below the calibrated setting of 1000 mbar (atmosphere), so the computer calculates the difference. If I had it tested at the calibrated ideals, the readings from P-Norm to P-Eng would read the same.
This rolloing road is calibrated every 6 months and unlike some older analogue types, the operator cannot "fiddle" the readings by manualy changing the air temp or atmospheric pressure.
