cheerful

Just noticed this today. Inside a tunnel where there is no GPS signal, Garmin shows the correct speed.

I'd guess the speed was an input from the car system. This also allow it to accurate predict the position of the car.

I've never used in-car navigation system before. Is that the case?

Altitude appears to be hit and miss. It showed correctly in one case and incorrect in another case?

Thanks

Driver5

Not sure about the MREC system, but in my BMW E60 it does this. I think it goes on what the speed limit of the road is to "guess" when you would be exiting the tunnel.

Could be diff on the Merc

Good lilttle feature regardless.

cheerful

The speed matches the speedometer. So the information must be passed on from the car into the GPS. This makes it possible to get predict the car location more accurately.