A:Answer I can only speak for myself and my cell plan. The GPS connects to the cell phone via blue tooth, just as if you had a blue tooth ear piece. It doesn't actually make or receive the calls, it just acts as a microphone/speaker. Cell calls don't use data, even without the use of the GPS, therefore, i can't imagine how ihe GPS could use data just by making phone calls. The actual driving directions aren't being sent/received through your cell, therefore, there should be no data usage for the GPS navigation.
