OSM on Garmin 52LM and 65LM

I have been using the OSM generic data map on my 52LM since 2014. As a driver in that time I have covered almost 300k miles and apart from new housing estates never had a problem getting to a destination. I can’t say the same for TomTom maps on the phone. I think that’s saying something for OSM and all the hard work folk put in.

I have just got a 2nd hand 65LM and whilst everything seems ok I couldn’t get the speed limit circle to come up. Always been there on the 52LM. I looked in settings and can’t see anything. I took the SD card out and then found the speed limit circle there.

So I’d be grateful if someone could advise me how to get the speed limit circle up on OSM maps. I have only used Generic Routable maps so far (because I’ve had no problems) - I did try the Generic New style this afternoon but no difference. I also want to get rid of the POI like parking places that come up which I’ve not had before… gone to settings tried to change it but doesn’t seem to work.

many thanks

Hi jessejazza,

please describe what you mean with “speed limit circle”. Does it mean that the devices displays the actual speed limit?
This information is not stored in the maps you mentioned, so either you used another map or the device got the information
from another map.


The road speed limit which was given in a red circle.

That information certainly does not come from an OSM map, see https://forum.openstreetmap.org/viewtopic.php?id=12618
You’ve got an NT map I suppose (City Navigator?)

I don’t know!

On the 52LM I have just used maps from

Sorry for my lack of knowledge but the speed limit has always been on the 52LM but not the 65LM. Hence the post.

There are navigators for phones which use OSM data, which include road speed limit (and other data), that cannot be included in the Garmin img map format.

Tried again yesterday as it’s Saturday and not working.

Looking at both devices’s directories it seems that the garmin maps are stored in a chip as they don’t appear in the directory. My understanding is that the device looks at the SD card first and if there is a map there it loads it first (bit like the CD drive on a PC).

The red speed limit circle as always with the 52LM was there whether the SD card was used or the Garmin maps. Alas with the 65LM only when using the Garmin map not with the SD card.

As someone pointed out in their reply the speed limit is not from map information. But when one is driving along and passes a road speed limit sign change the device’s limit changes too. It is somehow connected but HOW? Clearly the two models are slightly different.

As someone else has said phone apps do provide the speed limit but for 10+ hours use unreliable I have found and freeze prone. Fine for 1-2 hours private motoring but long periods on a charger also knacker the battery.

What is the difference between the generic map and generic new style? When does one use the typ file. There has to be an answer to this issue!

Hi jessejazza,

I don’t know if the LM52 allows this, but on my Oregon I can have multiple maps activated at the same time.
When I attach the device to my PC via USB it shows two mass storage devices, one is the SD card and the other is the devices
internal memory. Maybe you only see the SD card, but the device still must have some internal memory card.
If you want to know what the intermal map contains I suggest to remove the SD card. I am pretty sure that you will see your speed limits.

The generic map is built from the default style shipped with mkgmap [1], the generic new [2] is a moderate modification of this style.
The typ file is not related to this problem.
The Garmin maps produced with mkgmap use a rather old img format, newer maps from Garmin are all in the so called NT format.
AFAIK only this NT format supports to show speed limits, for sure mkgmap doesn’t store this information anywhere in the maps that it produces.

[1] http://www.mkgmap.org.uk/
[2] https://github.com/ligfietser/mkgmap-style-sheets/tree/master/styles/generic%20new

Many thanks for the reply.

If the 65LM works on NT maps is it possible to convert/modify the generic map to NT? Or did garmin change to NT to stop folk using OSM maps. As for the 52LM with OSM she has been totally reliable for every truck delivery 30-35 per day and covering 100K miles per year.

At present it would seem the generic map works as it reads the SD card (‘myMaps’ shows the OSM generic and CN Europe NTU loaded). But the speed limit is a bonus these days with mobile speed cameras… so far not caught and want to keep it that way.

Hi jessejazza,

I guess Garmin has invented the NT to allow new features like the speed limit sign display and others like activity routing profiles.
Unfortunately nobody has managed to understand this new format, thus we can only create the old one. I am not aware of any to tool that would convert old to NT format and I don’t see a need for that. What we need is a clever person with lots of time to find out what / how Garmin encodes in the NT format.


The 52LM has the speed limit display. As for the NT format it would seem Garmin invented it to improve the new look and charge more!

Garmin and TomTom I think have priced themselves out of the market. I’ve just been trying out a Sygic clone (free) this w/e which has a built in dash cam. Hasn’t crashed so far and the dash cam was better than the others I tried.

I’ll sell the 65LM and when the 52LM ‘dies’ I’ll probably use the phone.

Having used the 65LM for a few days I also noticed the following.

  • power supply has to be from a charger with mini usb - it won’t accept a micro usb with a mini usb adapter. (No big deal but I found the usb chargers poor and most only last a couple of months so I bought ones with the cable included and a micro usb connection as I have the phone to charge as well. Just saved cash buying one sort having got several mini/micro usb adapters).

  • It clearly reads the OSM maps on the SD card but removes the following functionality; road speed limit, the top left notification of junctions (e.g. turn left in 1 mile), and also the lane ahead function which splits the screen in two very useful on motorways and in London. Three functions that I find indispensable.

It’s been a disappointment for me as i liked the larger screen whilst in a truck, and so for me I think I’ll be switching to the phone when the 52LM dies.

Why Garmin can’t allow folk to do updates with a Linux computer I don’t know. After all that is what MacIntosh is! I phoned them last week and the guy simply wouldn’t answer and suggested I bought another model. I replied that phone apps are currently offering more functionality for virtually no cost.

Many thanks for your help.