A Tale of two Nuvis

 

I recently bought a second Nuvi 2797LMT, a refurbished unit, to use on an upcoming trip to the U.K.
The first one was purchased nearly two years ago and has given sterling service in all that time. It has become a firm favorite with my wife who finds it very easy to use and she has been borrowing it more and more mainly for the traffic and lane guidance features. So we decided to get a second unit for our trip.
I have been running the refurb unit daily to make sure there are no problems and my wife used it for a short trip that she has been doing weekly for the last couple of months. When she uses the older unit to navigate home it tries to send her on a longer route and she has learned to ignore this and take the logical way, but the refurb unit sends her the logical and quicker way. When she pointed this out to me I decided to run a test and on her next trip we ran both units simultaneously, and sure enough the refurb unit indicated the quickest route whilst the older unit persisted in going the longer way.
I have updated both units software and maps and made sure that all the settings are the same but the units still give different routes. Any ideas as to why two supposedly same make and models of GPS should give different routing instructions.

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Nuvi2797LMT (2) Nuvi260,Ford Sync3 Navigation. Captain Cook was a Yorkshire man too.

Hard Coded

bpaine wrote:

I recently bought a second Nuvi 2797LMT, a refurbished unit, to use on an upcoming trip to the U.K.
The first one was purchased nearly two years ago and has given sterling service in all that time. It has become a firm favorite with my wife who finds it very easy to use and she has been borrowing it more and more mainly for the traffic and lane guidance features. So we decided to get a second unit for our trip.
I have been running the refurb unit daily to make sure there are no problems and my wife used it for a short trip that she has been doing weekly for the last couple of months. When she uses the older unit to navigate home it tries to send her on a longer route and she has learned to ignore this and take the logical way, but the refurb unit sends her the logical and quicker way. When she pointed this out to me I decided to run a test and on her next trip we ran both units simultaneously, and sure enough the refurb unit indicated the quickest route whilst the older unit persisted in going the longer way.
I have updated both units software and maps and made sure that all the settings are the same but the units still give different routes. Any ideas as to why two supposedly same make and models of GPS should give different routing instructions.

Me guess is the Algorithm was changed and it's hard coded in the "BIOS"? or a change of CPU and it's hard Coded there. Something we do not have access to..................

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2639LMT, 67LM (X2) and 65LM

MyTrends?

Is there any chance you have MyTrends turned on for either or both of the devices? It is possible the "learning" the device does based on your driving habits has created the difference in behavior.

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Alan - Android Auto, DriveLuxe 51LMT-S, DriveLuxe 50LMTHD, Nuvi 3597LMTHD, Oregon 550T, Nuvi 855, Nuvi 755T, Lowrance Endura Sierra, Bosch Nyon

Very True

alandb wrote:

Is there any chance you have MyTrends turned on for either or both of the devices? It is possible the "learning" the device does based on your driving habits has created the difference in behavior.

This is very true as that feature can potentially modify a route. Also, is TrafficTrends disabled/enabled the same on both units?

My Trends Could Be The Culprit

Yes, I agree. I would look at the "My Trends" possibility as well.

If My Trends is on, and you

If My Trends is on, and you turn it off, a Hard Reset would be in order to make sure it's cleared out. A Hard Reset may be in order, anyway.

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Frank DriveSmart55 37.322760, -79.511267

I agree

phranc wrote:

If My Trends is on, and you turn it off, a Hard Reset would be in order to make sure it's cleared out. A Hard Reset may be in order, anyway.

I agree. When comparing routing of two devices with at least one having been in use for a while, a hard reset of each device (or a hard reset of one with the other being out-of-the-box new) is the only way to test the device alone. Not doing this adds issues of myTrends data, your speeds vs. speed limits, etc. Your device does learn from the usage it receives and this will affect routing and ETA times.

It's also critical to confirm that both devices are set to the same vehicle type, routing selection (fastest, shortest, most economical, etc.), avoidances, myTrends, TrafficTrends, etc. unless you're intentionally testing the effect of any of these on routing rather than the device itself.

Keep in mind that doing a hard reset loses all accumulated data the nuvi uses to accurately predict your routing and ETA based on your driving habits and it starts the learning process all over again. I try not to do hard resets unless I have a good reason for doing it.

Lessons learned

Lessons learned

Strange

Strange

Maybe

Me guess is the Algorithm was changed and it's hard coded in the "BIOS"? or a change of CPU and it's hard Coded there. Something we do not have access to..................
[/quote]

Both units have a check mark in the "Traffic trends" box.
I would have thought that the older unit would have "learnt" the alternate route that my wife was taking because traffic trends was in use for at least 6 months. The refurb unit directed us to the more shorter and faster route on its first trip along the route
All other settings are exactly the same on both units, but I am not to sure where to find the "My Trends" menu on the 2797.

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Nuvi2797LMT (2) Nuvi260,Ford Sync3 Navigation. Captain Cook was a Yorkshire man too.

Traffic trends vs my trends.

The way I understand it, the Traffic Trends feature is controlled by a data base you get with a map update. So if you have the same map version on both devices, you should have the same Traffic Trends data. My Trends on the other hand is based on learning from your driving habits. and therefore could cause two different devices to behave differently.

I think the only way to determine if some kind of "learning" is involved is to do what CraigW suggested and hard reset both devices. After doing this, you will need to go through all settings menus and reset them the way you want, making sure everything is the same on both units. Then, assuming the same software, map versions and settings, I would expect both devices to behave the same way ... at least for a while.

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Alan - Android Auto, DriveLuxe 51LMT-S, DriveLuxe 50LMTHD, Nuvi 3597LMTHD, Oregon 550T, Nuvi 855, Nuvi 755T, Lowrance Endura Sierra, Bosch Nyon

MyTrends

There are also some rules that need to be followed, the main one is that destinations must be saved as saved places/favorites and frequency of navigating to them. See

https://support.garmin.com/support/searchSupport/case.faces?...

That could explain the differences between two devices.

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Where there's a will ... there's a way ... DriveSmart51LMT-S, DriveSmart50LMT-D, Nuvi 2508LMT-D, 1490LMT, 1310, Montana 650T, Etrex 20

Sounds good to me

sussamb wrote:

There are also some rules that need to be followed, the main one is that destinations must be saved as saved places/favorites and frequency of navigating to them. See

https://support.garmin.com/support/searchSupport/case.faces?...

That could explain the differences between two devices.

It will be nice to hear back from the OP if he set the location in question as saved a place(favorites) for both units. Plus if he has also completed the daily or weekly pattern per the link you have posted.

This tid bit of info per the link may also get overlooked.

"Press the information bar at the top of the map screen in order to display alternative routes if one is available. Here you can press Go! to activate a route to your myTrends destination".

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Charlie. Nuvi 265 WT and Nuvi 2597 LMT. MapFactor Navigator - Offline Maps & GPS.

Always learn somthing new here.

charlesd45 wrote:
sussamb wrote:

There are also some rules that need to be followed, the main one is that destinations must be saved as saved places/favorites and frequency of navigating to them. See

https://support.garmin.com/support/searchSupport/case.faces?...

That could explain the differences between two devices.

It will be nice to hear back from the OP if he set the location in question as saved a place(favorites) for both units. Plus if he has also completed the daily or weekly pattern per the link you have posted.

This tid bit of info per the link may also get overlooked.

"Press the information bar at the top of the map screen in order to display alternative routes if one is available. Here you can press Go! to activate a route to your myTrends destination".

The location that we were heading to was the saved "Home" location. Thanks for the link to that piece of information. I have seen that message come up on my older 2797 on my daily trip to work but never realized that you could start navigating by pressing the information bar. I will try the new unit tomorrow and see if I get the my trends info and start navigating from the bar. I have my work place saved and a short cut icon on the where to screen.

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Nuvi2797LMT (2) Nuvi260,Ford Sync3 Navigation. Captain Cook was a Yorkshire man too.

Next thing you know

They will invent "Driverless" cars

So much for progress

windwalker wrote:

They will invent "Driverless" cars

Since the time I was a little kid growing up in the 50s, they've been talking about Flying Cars. Where the heck are those?

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nüvi 3590LMT / ecoRouteHD

the FAA

PaulieUrethane wrote:
windwalker wrote:

They will invent "Driverless" cars

Since the time I was a little kid growing up in the 50s, they've been talking about Flying Cars. Where the heck are those?

can't decide if they are 'drones' or not.

--
Illiterate? Write for free help.

Yeah, Until

PaulieUrethane wrote:
windwalker wrote:

They will invent "Driverless" cars

Since the time I was a little kid growing up in the 50s, they've been talking about Flying Cars. Where the heck are those?

Well, .gov got involved and it's history................

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2639LMT, 67LM (X2) and 65LM

Yeah, Until

PaulieUrethane wrote:
windwalker wrote:

They will invent "Driverless" cars

Since the time I was a little kid growing up in the 50s, they've been talking about Flying Cars. Where the heck are those?

Well, .gov got involved and it's history................

--
2639LMT, 67LM (X2) and 65LM

Interesting

Having only experience with an old unit that doesn't learn anything.

If you turn on MyTrends for a while and the unit learns your habits and then you turn it off... Does it just not learn any more but still use what it has learned? Or does it ignore what it learned and go back to "out of the box" algorithms?

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NUVI 350

Drivers habit

MikeSid wrote:

Having only experience with an old unit that doesn't learn anything.

If you turn on MyTrends for a while and the unit learns your habits and then you turn it off... Does it just not learn any more but still use what it has learned? Or does it ignore what it learned and go back to "out of the box" algorithms?

Older units don't have My Trends but they do learn ETA.

Can I train my Garmin to provide better estimated times of arrival (ETA)?

02/17/2016
Your device can actually learn from your driving and adapt its internal database to provide better estimates of your arrival time. The device will learn from a driver’s habits and adjust the ETA accordingly. This is done by observing what speed a driver typically drives in each speed category of road and using that data to compute ETA.
Check this unofficial test http://www.gpsreview.net/train-your-nuvi-eta/

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Charlie. Nuvi 265 WT and Nuvi 2597 LMT. MapFactor Navigator - Offline Maps & GPS.