It’s not uncommon for a GPS/Navigator app to want to push 300+ meg of map updates in your direction, though the better ones will ask your permission first. Just hope it doesn’t happen when you’re near the US border and roaming!!! Download a data enabler/disabler from the google play store. https://play.google.com/store/search?q=data%20enabler&c=apps I like the farproc version. Follow the installation instructions and put the widget on your home screen. The only reason for using one of these is that turning your mobile data on or off in later Android versions normally means going into Settings => More networks => Mobile networks => Mobile data & Data roaming, not exactly a one-handed operation. The enabler widget toggles your data on or off with one touch of the home screen. Leave mobile data OFF when on the road by default. Only turn it ON when you need it. Not bothered by unneeded instant notifications and NO $$$ for some app that wants to push a bloated update in your direction. Those can happen at home while you’re sleeping and the phone is hooked up to wifi and not chewing up your data allotment.Turning the data back ON while mobile will normally get your notifications updated within a minute, so you don’t really miss anything. Just get the info at your convenience, rather than being a slave to the device. Calls and text messages are completely unaffected regardless of the widget setting, but you won’t do picture messaging until data is on.