Hey guys I put Wheels on my car and they are 20 in the back and 19 in the front, I think it messed up my speedometer but I'm not sure...I do know that at 2,500 rpm's in 6th gear that it says I'm going exactly 69. if anyone with a stock crossfire could let me know what the speedometer says on their car at the same rpm and same gear that would be great. Thanks.

- Sean

 

You don't specify the size of these new tires other than diameter, so have a look at http://www.miata.net/garage/tirecalc.html - plug in the appropriate numbers and you'll have your answer.

 

It's a given that if you change the wheel/tire diameter, you are going to affect your speedometer reading. That can be compensated for on some cars by reprogramming through the OBDII port...not sure on the Crossfire.