Fellow Chicagoans, what region is your compass set to? It seems like we're on the border of regions 8 and 9. My car was set-up with region 8, but it seems a bit more accurate (for NE, NW, SE, SW directions) with region 9.

 

Are you talking about the navigation region? If so, it should be set to whatever area you traverse the most. I don't get how its more accurate with one region than another because your GPS gets the same coordinates no matter what region. I'll check when I get in the car.

 

W/o looking at the manual, I think it's 3. Not sure, check your documentation.

 

He's talking about the compass thats embedded in the rearview mirror. I switched between the two and noticed it was never quite perfect either region. I'm guessing the Chicago street grid isn't perfectly aligned w/ magnetic north which is understandable. Just use whichever one is more correct (driving east/west on a street shows up as E and W instead of NW/SE or something).

 

Yes, I am talking about the region for the compass in the rearview mirror, not the region for the NAV. If you hold down the "Auto" button on the mirror, you will see that first the compass disappears, then the region setting appears. Page 247 in the manual shows region 8 or 9 for Chicago. I get a more accurate reading with 9, but it's still off (not by Chicago's grid but by using the NAV GPS heading).

 

I don’t have the manual handy, but I doubt if it really matters if you set it to 8 or 9 because Chicago is one of those areas where one would have to go hundreds of miles east or west for the variation to change even by one degree. BTW, I looked it up (remember, I used to be a navigator) and the Chicago variation is currently one-degree west. That means you subtract one degree from a compass reading to get the true direction. In other words, your mirror readings, being magnetic, are quite close to true. In California, where I live, the difference is 15 degrees.

As for the car’s navigation system, the little direction icon on the upper left of the screen is probably getting its data from your mirror's compass system. The actual screen positions taken from the GPS satellites have nothing to do with the earth’s magnetic field.

 

Samsonite...I was way off!


I definitely notice the compass being off, too...the thing is, it's kind of off in most cars w/ electronic compasses in our area.