I know the following is going to sound really dodgy but here goes:

I have just had to change my instrument cluster as the speedo had
packed up. Managed to find a second hand one over the net and have
fitted it all working much better than the old unit and £600 cheaper
than a main dealer!!

However, the replacement speedo is reading 208,000 miles and my old
unit only had 114,000.

Does anyone know how I can get this corrected easily. I assumed the
mileage was stored in the ECU and not the instrumnet cluster.

Many thanks