MoabC7

I'm ****/cynical enough that if the OnStar TBT/eNav and is based off of MapQuest, I'm not interested. I want to know what the directions will be ahead of time so I know what to expect, and know they are correct. I've found MapQuest to be a POS compared to Google. Tried and failed at the OnStar site to setup a route. Not able to find address when all other mapping services had no problem.

BobCollins45

Interesting. And, my works just fine. Go figure!

CRABBYJ

MoabC6 - "What's good/great about the nav, leaving the rest of the Infotainment out of it. Of course the display is drop dead gorgeous. And the GPS accuracy is about the best I've seen. For example, as we neared our turnoff in SLC, we approached a spaghetti interchange. Multiple on and off ramps to the tune of four separate off ramps splitting and peeling off one another into various surface roads and directions. What a mess. The Nav system was flawless. Not only was the route depicted dead nuts on the respective road surface, but the turn by turn directions were spot on. Made a challenge into a walk in the park. And for the most part the information ahead of time was very timely and depicted very well. Would have liked the exit number to appear with the next exit's street name a little sooner, but that's a nick pick."

Thanks Bill for the excellent write and analysis. Back in October, 2010 my wife and I stopped at the Arches NP late one afternoon on our cross country excursion to San Francisco and back (8877miles) to PA. Our Magellan Maestro GPS was then programmed to take us to Provo. It wanted us to go 70W to 15N but using a map decided to short cut at Salina taking 28N. Being from PA this was a desolate drive especially at night. I didn't have the guts to drive Rt6 starting that late in the day. Even had a large number of bulk carrier trucks pass us going South carrying? But we managed and got there safely around 10pm. An adventure for sure.

Two questions: 1) What were the actual route #'s you traveled? and 2) being a pilot (Avatar) do you know if the C7's GPS is WAAS Enabled thus giving such great accuracy?

MoabC7

From Moab: US Hwy 191, I-70 West, at Green River, US Hwy 6 North thru Price to Spanish Fork, I-15 North to Provo or on into SLC. These are all very good roads, US Hwy 6 is wide and well traveled. Haven't done Hwy 28 in that area, but that way is 64 miles longer. Get away from SLC and there are lots of desolate areas in UT. Not as bad as WY but...close.

Haven't come across anything regarding WAAS Enabled for the C7. Could very well be. Maybe it is just a rendering improvement with the route highlighting. Many GPS's use a series of straight lines to depict the route. Have not noticed that with the C7. Very smooth and overlaid nicely. The guidance was right on and timed perfectly from what I could tell.

Bill

jackhall99

Bill, what GPS units produced recently depict routes using straight lines? My four Garmin units (lower end models) depict road curves quite accurately, give timely and accurate turn instructions including detailed instructions for spaghetti-bowl interchanges, know of traffic slow-downs in metropolitan areas, know almost every speed limit in existence, the overlay changes as you near highway splits that may be confusing, advise of red-light cameras, and many other features. And it is not WAAS enabled, just modern technology.

Again, I don't know the routing options available in the GM or other manufacturer's NAV unit, nor why it would offer much longer routes (unless "Use Interstates" was selected), nor why its trip duration times are so far off. For the price paid, that is poor.

Don't get me wrong. My units will want to direct me on a funny route on occasion, but I already know the general route I should be taking or want to take. My God made brain still trumps a man-made device in many situations.

BTW, enjoy the C7. Awesome car.

MoabC7

Don't know about any other "units". But with my 2012 Jeep Grand Cherokee's RHR nav unit if you zoom as close as it will allow, you can see where the straight lines are used. Some shorter than others. But it is still real close. Until you get to a true circle, enough straight lines can make a what appears to be a circle. Delorme's Street Atlas does this in a somewhat rough way to depict the route. Look at iMaps or Google maps close enough and you will see where neither highlighting really stays on the road. The C7's seems to though.

I've come to the conclusion that the error of "Fastest" routing is being caused by the gross inaccuracy of the time enroute calculation being done by the system. If the miles are correct, and they are, then if the enroute time calculation is off, and it is, then the system will look for a faster route. I am not privy to the algorithms or methodology being used, just seems logical to me. And no, even with all the traffic inputs off and all routing preferences set so as not to exclude any routes or roads, the system still picks the longest route. Logically it can only be the systems "sees" that the diagonal route will (incorrectly) take longer (even though the route is 64 miles shorter) than the drive due west and then north. And there is not a "Use Interstates Only" option. It has to be that there is a glitch in the software that is not calculating the correct time enroute for the diagonal route. Why else would the diagonal route show way more time enroute for a shorter route when the speed limits are in the database?

Bill

jackhall99

OK for the concept you are using "straight lines" on a GPS display. I don't zoom in that close to look. In normal viewing, I see a nice representation of a curve in the road.

As you state, the initial ETA calculations are simple math, based on miles and the posted speed limits along the route, and I don't understand how that can be too far off. My GPS calculates it rather well, to the minute on a 200 mile drive as it adjusts my ETA based on actual speed compared to pasted speed. And the absence of routing options is amazing.

SCM_Crash

Sent the car a navigation destination from my phone the other day. Got in the car, it pulled up the destination and loaded up nav.

So far have had no issues with my nav... Shame others have had issues. There's no perfect solution.

jackhall99

Good to hear.

fsvoboda

Just reading a report on Ford's Ka world car, which allows docking with mobile devices for easy interface with smartphone nav apps and the like. Really if Chevy is aiming to bring younger buyers into the C7 this should be a standard feature. I suspect that it wouldn't much change the take rate for factory nav.

SCM_Crash

Agreed. Chevy, however, could open their API to GPS software developers and charge buyers for an integration platform rather than a nav system.

Michael A

I can't speak to the quality of the GM system, but every navigation program I've used has sent me on wild goose chases from time to time.

I believe Navteq supplies the GM maps.

Michael

ZeeOSix

So were the two routes of 238~239 miles the same exact routes with just different estimated times? Maybe all those built in speed limits increased the time significantly over the same route (?).

KenHorse

Their API doesn't?

Bummer.....

SCM_Crash

Not from what I've been reading. I downloaded their SDK, but I haven't had a chance to play with it.

The thing is that it seems to be mostly HTML5 stuff. Based on their documentation, it doesn't look like there's any way to integrate into the HUD/Cluster in a way that would be work for a nav system. The nav stuff that is in there now isn't listed in the API documentation except, I believe, to set a destination. Still not really useful in this situation.

MoabC7

No, the built in speed limits in the nav system were spot on along the complete route. Google estimated 3 hours 52 minutes driving time. We drove it in 3 hours 50 minutes, no speeding, no traffic. So I would say it is pretty obvious the nav system has a glitch in the programing that is calculating time enroute incorrectly.

Now if I could just get to someone who can really do something about that.

KenHorse

Heh... I downloaded the SDK a couple of weeks ago but have been too busy (or otherwise distracted) to have more than a preliminary look. Now that I have, I see what you mean.

MikeyTX

Try a p/m with Talon90. His nav tutorials are classic. Plus he is the one at the bash that gives the learning seminars ...........

MoabC7

I already did that. Waiting for a reply. And he does do a super job!

MKenM

Navteq supplies much of the automotive industry with map data. I have Nav in my MB and although the Nav is easier to use than the Vette but just as inaccurate. I had a huge battle with Navteq. I bought the update from them and when I had problems they denied any responsibility for the problems. The story is too long but they are a horrible company to deal with for customer service. Hint they claim to provide data only not the program.