[DT]

I spoke to Garmin Tech support last evening concerning the 378's inability to accept PC generated routes. It is true that this unit will not...something to do with overlapping water and land maps.

An assumption was made that the 478 would not accept PC generated routes either. But that apparently is incorrect. Per Garmin, the 478 will accept your PC generated routes. The conflict between the land and water maps does not occur with this unit.

So, if you're in the market for a GPS that has all maps pre-loaded, XM radio, XM NEXRAD weather, and the desire to make up routes on your PC, the 478 might be a good choice.

 

[Jon]

So apparently, they handle the marine map data differently between these two units?

The 378 has the marine data (inland lakes) integrated with the road maps which messes with its' ability to use MapSource to plan routes. (There is a note to this affect on the 378 webpage)

The 478 states only that the unit has the marine charts (offshore data) pre-loaded in conjunction with the City Navigator map detail for road use. There is nothing on the 478 webpage that states that it will or will not accept a PC-generated route.

(MapSource is not included with either unit, so unless you have an earlier copy, it's not going to be an issue anyway)

I'd like to hear from a 478 user who has actually used a MapSource-generated route (without the unit recalculating it when it's loaded) to make sure this isn't just a mistake on the tech's part. (It wouldn't be the first time)

Has anyone actually done this yet??

 

[DT]

So apparently, they handle the marine map data differently between these two units?...

That seems to be the case as I specifically questioned the Garmin tech on this point. He went so far as to put me on hold to ask others and came back with the same answers…the 378 will not accept routes without recalculating them where as the 478 will accept and follow PC generated routes without recalculations.

Like you, I have gotten different versions of this same story so I’ll wait to see if someone on the board can confirm. If they can’t I may just have to order a 478 and verify it for myself.

 

[DT]

I'd like to hear from a 478 user who has actually used a MapSource-generated route (without the unit recalculating it when it's loaded) to make sure this isn't just a mistake on the tech's part. (It wouldn't be the first time)

Has anyone actually done this yet??

Seems no one has done this (or wants to report on it anyway). So, I ordered a 478 and will give it a try. Hope to have a report posted by the end of the week.

 

[DT]

...I ordered a 478 and will give it a try. Hope to have a report posted by the end of the week.

UPDATE - For those interested, I did order and receive my Garmin 478 with GXM 30. I'm happy to report that the unit did allow me to download a PC MapSource generated route without problems.

Note: as the 478 comes with V8 preloaded and I used V7 to generate the route, I did get the "maps don't match" message on the GPS but was able to navigate. I have a copy of V8 on the way from Garmin so that should address that issue.

It is really nice to have an auto-routing GPS with US maps loaded, XM radio, and XM NEXRAD weather all in the same unit.

 

[Jon]

That's great news - hopefully, when you load the V8 maps into MapSource, you won't get the map message anymore.

Did it have to recalculate the route after you got your message?

 

[DT]

That's great news - hopefully, when you load the V8 maps into MapSource, you won't get the map message anymore.

Did it have to recalculate the route after you got your message?

I selected "no", hit enter, then navigated per the route. Apparently V8 is a bit more accurate as it indicated a road that's not on V7. I think that's where the maps didn't match and gave me the error.

I did intentionally go off route at one point and the GPS did recalculate getting me back on track just as my old SPIII would do.

 

[Jon]

When you created your route, did you use many/any via points?

When it re-calculated, did it stay on your chosen route?

What I'm getting at is the limitation the 378 has - when it recalculates, it only connects the hard via points using its' own internal routing preferences. If you had selected your own special roads by just dragging the route onto the roads, when the GPS recalculates, you might not end up on those roads anymore.

That's the scenario that people are trying to avoid...

 

[DT]

When you created your route, did you use many/any via points?

When it re-calculated, did it stay on your chosen route?

What I'm getting at is the limitation the 378 has - when it recalculates, it only connects the hard via points using its' own internal routing preferences. If you had selected your own special roads by just dragging the route onto the roads, when the GPS recalculates, you might not end up on those roads anymore.

That's the scenario that people are trying to avoid...

Concerning the via points...I generally use the "Route Tool" to create my routes and then name them through "Save As." The route I spoke of above consisted of one Way Point, nine Via Points, and the destination.

When the GPS re-calculated, it brought me to the nearest rode that would get me back on track for my destination.

Hope that helps!

 

[DT]

UPDATE - I received the v8 DVD, loaded it to my PC, and then successfully created and downloaded a route to the 478.

A route consisting of one waypoint and nine "route tool" points took about seven or eight seconds to download. This route took up about 12KB on a 256 meg card.

Seems the 478 will only download a route to the data card via the supplied USB cable with the data card installed in the GPS.

 

[wv_wingman]

I guess I didn't even realize these units would accept a datacard. I wonder if my 378 would do the same thing?

 

[DT]

I guess I didn't even realize these units would accept a datacard. I wonder if my 378 would do the same thing?

Yes, the 378 uses a data card. You can download a route but the 378 will recalculate it and the result may/will be different then the route you intended.