GPS recommendations

My Garmin GPS is retired. I use my iPhone for navigation and never had a problem with it using up my data. I've used it extensively and can't see dragging another gadget around with me. I did buy a suction mount so I could attach it to car's dash and it was visible like a GPS. If you use Google Maps, you can download the specific areas for off line use. The only time I did that was in Corsica and Sardinia because of the lack of cell service in some mountainous and remote areas. The app automatically switched between on and off line as needed. It worked seamlessly. Only thing missing offline were traffic indicators.

Download GPS maps from Google Maps. Our brand new short-term leased car's GPS satellite data was already outdated due to the constant construction in Paris and was useless.

Just to second Kaeleku's observation, in addition to my usual activities, I used Google Maps intensively with Project Fi while traveling for 3 weeks last month. My data bill for that period is only $8 higher (for .8G more data) than it would be during a typical 3 week period at home.

Only problem with Profect Fi is that you need to buy a Google phone. Cheapest one available on their site is $649.

I use the CoPilot navigation app on my iPhone. I use it in the US and it worked great in Wales in the summer of 2016. The app and maps cost about $20. No data is needed during use.

I've found recently that every car I've rented over the last two years has come equipped with built in sat nav, even small cars such as a Renault Clio and Vauxhall Astra. It pays to be wary about the rental company, a recent rental with Hertz comprised of a Vauxhall Mokka which had built in sat nav however the maps were on an SD card which was removed by the employees and held at ransom with a hefty fee to release it. This infuriated me as the vehicle comes equipped with it as standard, the company hasn't incurred extra expense in buying a dedicated sat nav so why should the customer have to pay extra? I haven't experienced this with any other company.

Thanks for the helpful suggestions! I have an older (3 years old) Nokia Windows phone, and have not been able to update the maps due to the phone's age, which is the issue that prompted my post. I will definitely look into that Google phone option, but probably not before my upcoming trip, but I appreciate that tip and may finally be able to escape from AT&T's firm and expensive grip. I'm not surprised about Hertz removing the chip. They would not want to miss an upcharge opportunity! The suggestion re paper maps as back up is a good one, as I am old enough to remember relying on them solely, for past travel adventures.

My reasons to bring my own GPS, and how I purchased less expensive maps are in this thread:

https://community.ricksteves.com/travel-forum/transportation/garmin-gps-micro-sd-map-cards-for-portugal-and-morocco

I've used a combination of CoPilot and Google on my phone the last couple trips. I think Google does better searching for locations but CoPilot looks and sounds more like a GPS you're used to. It has speed limits, speed warnings and speed trap warnings. I decided to get maps for all of Western Europe (downloaded at home) that cost $30. Google works but it lacks some of the lane guidance and speed limit features as well as more understandable voice directions.

You need to use data when you are searching. When you navigate, save your data by turning it off. Your phone can navigate fine without it. If you leave data on, your phone will use data to refine it's position but you don't need it.