on TOM TOMS you can set the display to show miles per hour.....I am curious as to how accurate this will be, as it seems at least 7MPH 'slower' than my actual car speedo. Can I assume the Tom Tom provides a 100% accurate speed readout?

Been going thro speed cameras on way to Huddersfield in 30 MPH zones (there are LOADS of them heading into Hudd from Sheffield via Penistone )this morning and my car speedo was showing a steady 37 mph while the Tom Tom was telling me I was doing dead on 30.......I just hope the 'modern' equipment is accurate! none of the cameras flashed me though so I must assume my car speedo is naff.......

Hey there, all cars have speedo's set about 5% lower than the actual speed they are doing. I have a TomTom and it shows my speedo at 5mph slower than the actual speed of the car.

I believe manufacturers have to do this for a variety of reasons, but mainly if you had a speedo showing 30mph when you were actually doing 35mph and you got caught speeding - you could sue the manufacturers!