Under reporting

[edagrade]

My DriveSmart 65 has begun displaying vehicle speed somewhat slower than the vehicle is travelling.
This occurs when the unit first starts and lasts for 2-3 minutes of travel before displaying speed accurately.
The error value ranges from about 3 to 10 kmh.
Any ideas on could be causing this?
I this a sign of the device ageing or about to die ??

 

[Nuvi-Nebie]

As time goes on the GPS gets more satellite 'fixes' so it may be that in the first few minutes the unit does not have an accurate measure of where it is and this could affect speed calculations, this would be more noticeable when the unit hasn't got a clear view of the sky due to buildings, trees etc.

 

[edagrade]

Thanks for your thoughts. Seems it is nothing to be concerned about.