Hi, I have a beautiful e39 - but the speedo is 'under-reading'.
If I drive at the correct speed as shown by the speedo I pass all the other cars and I get warnings from the relevent signs saying 'you are driving too fast'.
If I do the board computer trick I see the speed electronically is 5-8kmh 'quicker' than that shown in the speedo.
Maybe the tyres are the wrong profile, what should they be?, but wouldn't that mean both the speedo and electronic speed would both be out and still the speedo would be higher than the electronic reading (which I expect is the more accurate) - as is the norm.
Now except from being illegal, I understand, it is a bit annoying as I already pay enough for speeding tickets.
Is it possible to have the speedo recalibrated by BM or so?
Any ideas...