Is buying separate GPS good option?

Since it seems it is almost impossible to set smartphone private considering geolocation, I wonder if buying separate GPS is good option.
Do anyone have any information that this option would not be private (e.g. that some GPSes has also wi-fi module which track you or something like that). I guess new maps must be somehow downloaded? Is it possible not using wi-fi/ISP?

Do you know any small/good GPSes?

My subquestion is also which private maps which would work properly (best downloadable from F-Droid/Google Store) good? It’s worse option than separate GPS, but I guess still a little better than Google Maps.

Assuming that you mean “(automotive) navigation system” when writing “GPS,” then it depends on the device you buy. As you wrote, some devices come with their way to update the maps stored on the device.

“Is it more or less secure than my smartphone’s GPS chip?”: In your smartphone, you have a separate GPS chip with dedicated firmware. It communicates via APIs with your smartphone’s operating system (e.g., Android or iOS). The same is true for the GPS chip in the navigation system. So you have an identical scenario in this case.

How it is identical?
The only problem I see is download method of updates. The best would be to just download some pack from website and install by USB (anyone knows such devices and/or without wi-fi?), the bad would be wi-fi (since google scan for wi-fis signals).
However, separate GPS would not have sim card (so no ISP can track you)+no android system and identification number connected to your device (which is known to be yours by your sim card).

I consider scenario when you buy GPS device is some big city, than
turn it on during drive (since you probably do not need it near your home anyway), charge in your car.
If there is no wi-fi in such device, one can only know that GPS device no.xxx is in such place, but no other information.
Unless you would be identified by your habit patern, cameras downloads corellated with location, satelitte photos or spyied by purpose, but we do not talking about such treat level.
However, you ISP cannot track you as well as Google, Apple, other application and your phone agent. GPS can be tracked probably somehow, but it would not be connected to your identity anyway.
Am I correct?

As mentioned before, the smartphone as well as the navigation system have a GPS chip that runs its own firmware and communicates via APIs with the user operating system of the device. In both cases, there may be no updates for the firmware of your GPS chip.

Who is “one” in your threat model?

In general, the GPS chip in your device receives signals from satellites to pinpoint its location. The GPS chip doesn’t send any signals back to the satellites. This applies to the chip in your smartphone as well as to the chip in your navigation system. “One” can’t simply open a map to see your location when using any GPS device.

Blockquote

In general, the GPS chip in your device receives signals from satellites to pinpoint its location. The GPS chip doesn’t send any signals back to the satellites. This applies to the chip in your smartphone as well as to the chip in your navigation system. “One” can’t simply open a map to see your location when using any GPS device.

Blockquote

Ok, I assumed that it sends signal in both directions, like wifi or phone. If it cannot, than it seems it is annonymous.

But even if GPS device and smartphone ones are built the same way, the smarphone spreads also telephone signal. In this case everyone who has access to ISP/Internet provider, can now your average location by towers.
The other problem are tracking applications (but let’s skip them for now assuming they are all off) and the system (Android) which scans for nearby wi-fi MACs even on airplane mode.
I’ve also heard that even on Linux installed on smartphone Google can still scan wi-fis (or rather be seen by other wi-fi, not sure here), because it is implemented in the device, not in the operating system.

So, GPS device may be the same on smartphone and it may not send signal back to satellite, but the problem is that smarphone can be tracked e.g. by wi-fi, and GPS alone not.
And even if somehow GPS alone could be tracked, it is much harder to connect it with your true identity.

I think the potential problem arises when you try to update your GPS device. How does the update happen? Does it send telemetry/metadata from your device back to the manufacturer server before/during/after the map update?

If you can update your device “offline” via a USB, it should be just fine, but if it connects to the internet like a regular cellphone via wifi or cellular data, it should have the same issues as a regular cellphone.