I bought a 1994 Del Sol SI. The stock tires are supposed to be 185/60R14. This one has 185/65R14. From what I understand the speedometer should be telling me I am going slower than I actually am. However my speedometer is telling me I am faster than I actually am. Approximately 5 MPH over running at 60. I based this on my newer van following the wife which I know is accurate. I have new 15" rims coming and am going to put on some new tires. 195/50R15 will put me back to the correct stock overall, but that is going to make the speedometer register even further off. Can somebody tell me what can be done to fix / adjust the speedometer to reflect what it should be.

 

search for speedohealer there was a guy on here who used it to fix his jdm cluster so that it was in mph instead of km . lots of bike guys use them also

 

I have the same issue, and I'm actually running the same rim/tire size that you are. I was talking to one of my friends about it that used to work at a shop and he was telling me that they had a calibration tool at the shop he worked at. I would go to a local shop and ask them about the situation.

 

How is this supposed to work? Is this a devise to calibrate my speedometer? or does it need installed?

 

I like that Idea better. Thanks civicjunkie