ODB to GPS speed calibration

[NRGDEAD]

By tuner you mean a guy or company? Because I couldn't find someone who does this. Even my local Suzuki guy couldn't make that adjustment. Because my tires indeed don't match the original tires, and this concerns me a bit, since I get quite a few more kilometers on the odo than I actually drive.
I guess I can't adjust that myself using OBD, can I? The revs/mile, not the odo. ;-)
Also, this would bring OBD and GPS a bit closer together.

[gplracerx]

By tuner you mean a guy or company?

It's a device sold by Ford Racing Performance Parts specifically for recent vintage Mustangs. It reprograms the ECU as well without having to change chips. Since it's a Ford product, it's not supposed to void the warranty, although I have enough miles on the car that's not an issue any more.

A quick search on 'Suzuki performance tuner' had a lot of hits, but I didn't see anything from Suzuki. It's unlikely an aftermarket tuner or chip would change the drive configuration. There are risks to using non-oem chips. For example, they might give you a horsepower increase that will cause burned valves when used for more than a few seconds on a dyno.

[NRGDEAD]

Ah, that's nothing I want to do. The car (hopefully) still has warrenty.
And I'm from Germany, it has to be perfectly legal and double checked and everything, or they might put me in jail for fraud. ;-) So I'd rather keep it +10 kmh off the correct speed than messing around with it myself.

But thanks!