I think it's two different things. Speed limit, which as you correctly point out, displays max speed allowed. Speed warning, which is an audible notification of a speed limit the driver has set.

The 991 PCM has both of the above functions.

 

Really? How do you turn on the audible speed warning notification?

 

Hope this map helps. Follow, Vehicle, Limits, then set Limit 1 and Limit 2

 

I set up the speed warning/speed notification. Unless I set it up wrong, there is no audible notification, just a visual one on the Multi Function Display once you hit the speed notification you set. It is actually pretty neat.

 

cool map, thanks Haku!

 

This a cool feature but found that it wasn't very accurate for my area. There was often a 10 mph difference.

Maybe after they do a map update????

 

I have been using it since I got my car a week or so back. It has prevented me using radar detecter (9500cxi).

Steve, I think it's not GPS but programmed into maps for the navigation system (perhaps that's what you meant??); When the GPS detects the road you're on, along with the name of the road, the speed info stored in nav HDD is displayed. I absolutely love this feature! This can also be shown on PCM screen when "car" button is pressed. I think only issue could be if maps aren't periodically updated and speed limits change, this would show you obsolete info...but I also saw import address feature in the PCM...not sure if we are able to update maps on rolling basis as well??

 

Yes, it does rely on past data and that data can change for different reasons (e.g., new construction around Brenham, work areas, etc.). I also find the database to be incomplete for some map areas that have been around for quite a while and are very well traveled. It is a great feature though and I would much rather have it than not. It would be nice to see updates but since Porsche doesn't tell you what is updated in the map updates I tend not to buy them.

 

I don't know what's it based on etc etc...all I can say is that most speed changes happen right where the sign is on the right side of the road.

Pass the road sign & the indicator changes (not 100%, but in my case here in WA pretty close). I was told GPS by the dealership.