[Edix]

I found out that the magic number is 191.
The way I found it is by checking the distance the car passes at its max speed over 1 second.
I found out that with Sabre you drive 51 meters over 1 second and using a simple converter I found out that the max speed is 183 km/h.
I also did the same test on a Sultan which drives about 50.25 meters over 1 second at top speed wich is 180 km/h and so the magic number of 191 worked perfectly fine for me.