I just got back from a 1 week 1600 mile trip. From Santa Clara, CA to Sedona, AZ to Las Vegas (CES), back to Santa Clara. The car was smooth and comfortable for the long 12 hour drive down and the other long drives (5 hours and 8.5 hours). I have only one complaint and that was with the GPS.

Around the bay area it's been perfect with the routes chosen and I thought it was killing my older Magellan 760 for update speed, graphics and voice quality. However, I found a few flaws that made me think twice about this GPS for longer trips. It tried to route us to AZ by going all the way out of the way to LA then over to Phoenix and up to Sedona. That's about the longest route you could take to get there from the bay area. My Magellan always took us the fatest way by crossing over hours earlier and going over the Tehachapi mountains to Flagstaff via 40 and down. That's the proper way to go but this GPS was completely clueless so if you had not known better or had not consulted a map before going you would have driven about 2 to 3 extra hours on that trip. Not good! It also missed the best way home and would have wasted us about 45 extra minutes had I not bypassed the directions given. It's as if it likes only major highways on long trips and disregards the smaller and more practical highways. Not sure if there is a preference I have to enable on the oem GPS or not but it's definitely not getting us there the "shortest/fastest" routes on this trip. There were a few other weird GPS glitches that came up as well, but I won't get into it at this time. After seeing the latest Magellan and Tom Tom GPS units at CES priced about $500, I am now wondering if this system is any good at all for long hauls. It certainly failed this first test.

Now as far as the mpgs I was much more impressed than I expected to be considering the first 2000 miles around the bay area I couldn't achieve anything better than 22.5 mpg. Here's what I did on this trip:
26.5 - all highway
25.8 - all highway with much of it climbing to 7000 ft
22.3 - around town mostly
22.5 - " " "
29.9!! - all highway
23.4 - mixed
25.9 - all highway
That's just over 25mpg for the whole trip - not bad considering all the uphill and around town we did in between the longer drives. This was with 2 people and a maxed out packed trunk with some extra stuff flowing over to the back seat as well. For the first time ever I kept close to the speed limits on this trip (only about 5mph over). That means about 70-75 on I5, 75-80 on I40, and 65-70 on the rest of the highways.

Now I just need to find out what can be done about the goofy gps routing on this trip. I'll be doind some investigating by trying to program only to state borders top see if it makes any difference, but I'm not too sure it's going to matter.

 

That's decent mileage.....

C.

 

You're GPS is probably set to automatically use the "fastest route", but if you don't like the route it gives you you can also tell it to recalculate it. In the route screen press "Recalculate" it will show the route. From there you can then choose: "Start", "More Routes", or "Route Info." Another idea that may help would be to specify a couple of way points along the route that you want, then it will calculate the route to go through those points. I haven't messed around with that much because it's been pretty good for getting around town, but it may help for the longer trips.

 

Yeah, use your voice command and say "fastest route", "shortest route", "minimize freeway", whatever. I know that when I'm driving in San Francisco, I know many shorts to my destination, so I skip the GPS altogether. Sometimes, a human knows the best route, because you're familiar with the flow and speed of traffic, rush hours, detours, etc.

 

I had issues with the GPS routing from Santa Clarita, CA to Las Vegas also. the locals told me to take highway 14 to 58 then 15 and that was the fastest. GPS took me through rural roads and through a couple of cities I never knew existed. On the way back from Vegas I took 15 to 58 but GPS kept on forcing me to turn around and go the way I came up. I just turned off the voice prompts cause it was annoying.

 

All GPS routing algorithms are funny. They assume an average rate for each type of road. I think the G35's uses 55 MPH for freeway, 25 MPH for highway, and 20 MPH for normal roads. Inside an urban area, this is probably a good estimate, as your speed on highways will be lower due to stoplights and congestion.

On my Garmin, I get the opposite effect, as it has a high value for highways, and a low value for surface streets. Given a choice, it will route you through a highly congested highway instead of a shorter normal road. I feel that there really should be 4 categories (Freeway, Rural Highway, Urban Highway, Road).

 

Usually, if I see that the NAV is picking up a retarded route, I just continue on what appears to be the most sensible road and let it adjust itself accordingly.

 

The average speeds can be adjusted to what ever you want. So if you like to drive down the freeway at 8mph to watch old granny's pass you, the navi will accommodate you.