hi had my car just over a year now and seemed to have done a fair few miles so out of interest i decided to try and check if the speedo was reading correct.i did a set route (on customer roadtests) and they all produced 1.2 miles exactly tried mine and came back at just over 1.3 miles might not sound a lot but over 12 months!!!have tried speedo reading using sat nav reads 28mph when doing 30 on speedo , 47-48 when speedo shows 50 and sat nav reads 65-65 when doing 70 .any ideas why mileage should be over speed convertor or something else any help/thoughts appreciated 