Frequently Asked Question
The speed on the computer differs from the cars.
Last Updated 12 years ago
The speed shown on the computer is
dependent on an accurate distance calibration. If a correct distance
calibration has been made the speed on the computer is more accurate than the
one shown on the car speedometer.
“Speedometers have a margin of error. Different types of speedometers are used in the automotive industry, and although the exact margin of error varies by type and manufacturer no option provides a 100 percent accurate speed reading at all times. Variables on the vehicle that change over time affect the accuracy of a speedometer.”
Read more: http://www.ehow.com/info_12209329_accuracy-vehicle-speedometers.html#ixzz2k2BW0Yi7