Frequently Asked Question
The speed on the computer differs from the cars.
Last Updated 5 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