Mine shows about 9% error...I got clocked at 75 when my cruise was set at 69. I just mentally adjust for 10% of error when I'm driving, and chalk it up to the 225/50-16s on a car that originally had tall tires on 14" rims. It's only an issue when I'm on open road anyway.
"Think of it, if you like, as a librarian with a G-string under the tweed." Clarkson on the Mondeo.
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