So have just been for a run down the motorway and here is the result Changed as above from 1 to 3 and at 100kph the OBDII says I am doing 100kph where as on the 1 setting I was doing 104 on the speedo when OBD II said i was doing 100.

My car is an Rline with 20in wheels with 255/40/20 Pirelli tyres