I am running 195 / 60 14 's which are too small. The Impreza I know are at least 15" probably 60 series from factory, but not sure. I have tried the WRX forums, but the forums are being restricted to paid memberships, to post

Speedo is too fast for actual speed . Not sure of the formula conversion from 3.7 to 4.111.
3.7 devided by 4.111 =.900024325, (9% difference) but speedo isn't nearly 10% out. probably 5 - 6% at a guess.
At least this would be a base to start, thanks
cheers
Chris
