- Why does MyGeotab speed profile not show the speed I was driving at?
- Speed Profile
- Driver Feedback
The Geotab devices calculate the speed the vehicles are driving at by using GPS coordinates. This is more accurate than most vehicle's speedometer that can be affected by various elements, such as wheel size, and transmission/drive ratios.
Wheel size itself can be modified by wear, tire pressure, weather conditions, etc.
Please note that Geotab also expects a difference of about 5% between speedometer and GPS based speed on a new vehicle.