992 Speedo, Odometer and SatNav

[PhilipM]

I was on a long drive back to Andorra yesterday - about 1020 Km.

As I recall in the distant past the odometer operated the same drive as the speedo. So if your speedo overread - as we were taught all speedos were designed to do slightly - your odometer should also overread.

So I checked the odometer against the distance to get home on the Satnav and it was bang on - 500 Km on the odometer equated exactly with 500 less Km to go on the SatNav.

So it would appear that the two are linked as the SatNav always operates whether you are using it or not, and can even operate with a Satellite signal through the use of a gyroscope when you're in a tunnel.

Does this mean that the speedo also operates off the SatNav which would render it accurate (within the very slight inaccuracies within the Sat Nav system)?

 

[cymro]

I don't think the speedo works off the sat nav. On my car the speedo is about +2 MPH more than the GPS speed on my Road Angel. Also when on Waze the speed indicated is the same as on the Road angel.

When in areas where there is no GPS signal, the speedo always works.