sorry man, I didn't read this before. I had the same problem as you on 225/50R16's and installing 18's with 225/40R18s brought the speedo back to spec.
I swear, some of our cars came with higher profile tires, and they flash the ECU accordingly from the factory (even if the dealers deny that it can be done). I just think that your profile is too low. but would you really want a higher profile?
you could at least callyour mitsu deale and see if they would flash the different tire size into your ecu. the worst they could do is have a stupid look on their face, and tell you that it can't be done.

btw: I installed Stratus final drive gears, and now I'm back to 5 mph ove

peace
WIKKI


THAT is not f**king THAT!
THIS is f**king THIS!