This item relates to the speed recorded on my Tom Tom SatNav versus the Speedo on my S Type Jag.
When the Jag sits at 70MPH the Sat Nav speed indicator is only showing 67mph. Is the SatNav the correct one? idea

I have yet to make this comparison between the Sat Nav and the MOG (but I will).

Both Cars have their original wheels and tyres.

http://franks4x4-solograndetour.blogspot.co.uk/
Combat Stress-http://www.justgiving.com/Roadster100