I just programmed my brothers 01 Ws6 m6 with ea Vinci Tuner.

I did not mess with tire size or gear ratio. His car is off about 12mph.

On my 01 A4, I never had any problems with it. I put my car back to stock to tune his, and now his speedo is off.


Anyone have any ideas or help?

 

Maybe some data "residue" that didn't clear out.
Did you try programming it with the car's actual
values, anyway?

 

make sure the tirs size is set at 25.75 mine without me touching it was at like 24...i have 3.73 gears also with my auto and with my car tuned for 3.73 gears and Stock height 25.75 tires it right on the money

 

some of the older versions, there was a scaling issue with manuals. need to get the version date and julien date that comes across the screen to see what version you have. then call, vinci and see about an update to the tuner.