Gear ratio change

[mituc]

Has anyone played with the gear ratios in the tune for any other purpose rather than in the case of a transmission swap from another model?
What I want to do is to get the speedo readings closed to the GPS readings on my 3MPS. My CX7 is almost spot on from the factory so I'd like to get the MPS closer as well.
The problem is that I have no idea of what other implications this may have: stability control program, fuel range calculations, accel/decel corrections on gear changes, or whatever.

So if anyone played with these please post. Otherwise I guess I'll be the first

[Ugnius @ VersaTune]

As far as I know the speedo reports the speed that it gets from the ABS control module, not from the engine control unit. The error in the speedometer readings is a "feature" and the readouts are always higher for liability reasons.
I am not aware of a simple way to reflash the ABS control module.

[mituc]

Indeed, no matter what I do to the gear ratios the speedo will indicate the same. But I had to try now having enough information about how things work there.
I know that the deviation in the speedo is programmed there, the OBD speed is pretty much on par with the GPS speed (200Kmph on the GPS is 202-203Kmph OBD but I run 225/40/r18 tires instead of 215/45/r18 the speedo was calibrated for). I was just hoping that the speedo will get its speed reading differently somehow.