Originally Posted by calemasters

With the NAV, it is not that the declination (variance) setting is disabled on the compass display, it is that the NAV does the declination calculation automatically based on the gps geo-coordinated and then sends the correct heading to the compass display on the driver information display. Therefore, the compass display is always correct, thanks to the NAV's gps, and never needs a manual variance calibration.

Originally Posted by Mark Doiron

You have restored in faith in Jeep engineers. Thank you. Now, I assume that the drift in magnetic declination will be included in the periodic updates to the nav system firmware. It's slow, but over a couple decades it will need to be corrected. I hope that they are still doing nav system updates by then. LOL.