True will still need calibrating up though, no guarantee it will be reading correct if you plug it into yours, but I prefer the gps to calibrate my current speedo
My mate uses his in his wagon, with the tachograph they have to be calibrated, and checked on a regular basis, its a sure way to know that the tacho or speedo is behaving, how many of us have found that the factory fitted speedo is out, even in my fathers 02 zafira its 4mph out at 70
