In the manual it says:
I have yet to see this actually work. It's a bit annoying when the speed limit doesn't update in the display, even though I've turned into a residential area. It would be great if I could tell it to use the Nav for the speed limit all the time instead of using sign recognition. I've turned off sign recognition to see what would happen, but the speed limit display goes away completely, instead of using the information from the Nav system. Also annoying is that the Nav map display does not show the speed limit like other systems do; you have to display the map in the gauges area to see it. It's also not clear to me if this display is actually showing the speed limit from the GPS system or is it showing the speed limit from the road sign recognition? The manual is not clear on this.When no speed limit signs are detected, relevant speed limit information from the navigation system is displayed in the message center and the HUD.