Speedo and obc speed reading

[chapmanw]

Just wondering if it is common for a difference in speed reading from the speedometer and the obc (function 8) I know that the speedometer can be calibrated from the obc but the directions appear to be calibration for the instrument panel (i'm guessing the speedometer with the needle)

So, which reading is the correct one? Anybody out there notice this. btw, the difference in reading is about 5km/h when i'm going 120.


thanks,

[shogun]

if you didn't change wheel/tire spec

they are both very precise. BC is more precise.
Depending on the country spec/law, the speedo should NOT indicate less than actual. So depending on the speed you have, it shows usually a bit more than actual, so the manufacturer is on the save way.