Which of my maps can I erase to make more room?

First of all, make a complete backup before you erase or change anything.

When you display Map Info on your nuvi (Tools>Settings>Map>Map Info), what maps are shown? Of these, which maps do you wish to keep? What are the file dates and sizes of the gmapprom.img and the two gmapsupp.img files?

You can safely delete the .sum files, although they are very small and won't gain any useful storage. They are checksum files from running diagnostics and are not needed.

Gmapbmap.img is your basemap. Do not delete it. Gmaptz.* is a time zone map. AFAIK, the nuvi 260 does not support the automatic time zone feature that this map is part of. How did that map get on your unit?

I'll follow your advice a bit later this evening. I have no idea how the gmaptz.img got on the 260w.

Thanks again!

That's the Time Zone file, and is updated via MyGarmin.

But I don't think that file should be on a nuvi 260. If I recall, the automatic time zone feature was introduced on the 7x5 series. Nuvi's that don't have the feature don't get the gmaptz file with Webupdater or map update.

Sorry, missed that in your post.

They are a few bytes long and are not worth your time.
The actual map files are the *.img files – however the gmapbmap.img shouldn't be touched.
The other *.img files may be deleted, provided you know which map each one is so that you do not delete maps which you still need.
And if you do take a backup as suggested, then nothing can go wrong even if you make an error

Do NOT delete the *.unl and *.gma files as they are required by the GPS unit's map unlocking process and you really won't gain any storage space by removing them. However, with that being said, I am not so sure that the 2x0 series even uses the *.gma file unlock process. Maybe alandb can chime in and see if his unit also has the *.gma files. I do seem to recall that they are placed on the GPS, regardless of if the unit uses them. Still, just leave them alone...and do make a backup of all files on the unit before fooling with the nuvi's file system.

If you were to remove the .GMA file on a 2xx unit the map would report that it was not authentic and needed to be unlocked. This is because the maps themselves have the authentication code within them, rather than being part of the device firmware.

That said, delete either gmapsupp.img or gmapprom.img, depending on which map is older. More than likely, gmapprom.img is the 2007 map that came with the device.