Tested with a Renault Clio II 1.5 dCi on the same, short trip multiple times with similar conditions (weather, traffic)
The tests were reproduced later with a different car: Mazda 6 Skyactiv-G145 2.0
Significant differences from the fuel consumption recorded via CAN (and dashboard if it’s shown there)
The difference varies in every vehicle.
The difference is not constant even for the same vehicle -> Can’t be calibrated.