2013 Rubicon, Speedometer tied to nav ?

[20jk08]

I didn't realize this,,,,
Checked today with my other navigation system, and sure enough, I was 9 km off speed.

So here's the story.
I picked up a new to me 2013 10th Anniversary edition, with budget boost and on 315/70R17's Mickey Thompson ATZ's, ( both soon to be swapped out)
Driving the 400 km's home, at what the speedo, and the nav told me was 100kmph, seemed kind of fast, but hey, I was trusting the nav, and thought maybe the previous owner had programmed it and neglected to inform the dealer, and didn't include the programmer in his trade in,, the speedo and nav were the same,,, and no TPSM lights on,,,
Figured I would call the dealer to try to track down the programmer, eventually finding out the jeep was never programmed. Hmmmm
Today, I plugged in the Garmin and went for a boot. Yup, The Garmin was reading 83 kmph and the speedo and nav system was reading 90kmph. I know the Garmin is bang on...
So are the speedometer and onboard Nav tied together, or am I on crack, seems wierd,,

 

[TheStick]

I didn't realize this,,,,
Checked today with my other navigation system, and sure enough, I was 9 km off speed.

So here's the story.
I picked up a new to me 2013 10th Anniversary edition, with budget boost and on 315/70R17's Mickey Thompson ATZ's, ( both soon to be swapped out)
Driving the 400 km's home, at what the speedo, and the nav told me was 100kmph, seemed kind of fast, but hey, I was trusting the nav, and thought maybe the previous owner had programmed it and neglected to inform the dealer, and didn't include the programmer in his trade in,, the speedo and nav were the same,,, and no TPSM lights on,,,
Figured I would call the dealer to try to track down the programmer, eventually finding out the jeep was never programmed. Hmmmm
Today, I plugged in the Garmin and went for a boot. Yup, The Garmin was reading 83 kmph and the speedo and nav system was reading 90kmph. I know the Garmin is bang on...
So are the speedometer and onboard Nav tied together, or am I on crack, seems wierd,,

Yep, unfortunately they are. It does not provide a true GPS speed.

 

[20jk08]

re:

Thanks for confirming that for me !!
I was wondering why my gas mileage was so bad,,,

 

[RMC2]

I have been wondering the same thing lately on my '13. Now I know what I suspected was true. Thanks for the info.

Just one more reason not to get factory nav. I should have ordered my newest jeep.

 

[11rubicon]

I was literally about to post something about this today. I've got a 2011 with nav and was always wondering!

 

[uechiyondan]

Thanks for the info. Who would have known? Now I will need to check too! I was wondering about the mileage as I would not have thought bigger tires would not have made that much of a difference.

 

[mudmobeeler]

I was wondering this myself as it just doesn't seem like I'm going the speed it says. Both the speedo and the NAV are reading the same. I did reprogram but may need to play with it some more as I done it quickly just to get it driving. Think the shop that installed my tires pumped them up a little too so I probably need to drop them down and then remeasure and reprogram.