Noticed my digital speedo is not in sync with the gage nor GPS readout on my phone... anyway to calibrate using Foxwell?

 

I don't believe there is, have never seen it on mine. It's a 530 I think.
Have you changed tire sizes? They are typically within a few mph around 50-60mph.

 

You can search for my earlier posts on this topic, but in short, no. It can only be fixed using the full AM software and requires a factory approved car specific generated file. The factory will not approve that file.

Short explanation. The penalties for European car makers if the car speedo reads lower than reality are so severe that they ALL set them to over read by 3-4% to be safe. Someone on a Porshe forum got interested and precisely measured the odometer value and the speed indicated and discovered that the odometer knows about this over read and compensates so the odometer is correct.

the manufacturers like it because they do not get fined and it makes the cars seem faster to those without precision GPS tools.

Annoying, but true.

Philip

 

This is absolutely true!

Years ago there was a class action lawsuit against a mfgr. Think it was VW but not sure. The suit claimed damages in the form of speeding tickets BC the speedometers read lower than actual speed.

In all of the cars I've owned/checked, the indicated speed is always higher than actual.

To answer the Q about calibration:

Calibration occurs in the EMS and can be calibrated in "PROTECTED" data tables only accessible by the mfgr (and NO, the field service systems CANNOT access EMS data tables as it's considered intellectual property).

I access it on SOME cars (not all) using hack SW.

Here is a page from the data section where speedometer calibration occurs:

 

i actually did change tire size, but just the fronts...i didn't realize just changing the fronts would have affected the speed. I guess it's tired to the ABS tire rotation or something.

 

I am running 245/35R19 in front and 305/30R19 in rear and my speedo is bang on