I saw a tuner the other day that looked like it somehow adjusted your computer for different tire sizes. If I put some 18" wheels on my stang do I have to do any type of calibartion to the computer?

Newb question but I really have no idea. Thanks.

 

It's not just the wheel that's important, it's also the tire. If the "overall total height" of the wheel/tire you choose is the same as what it's replacing, then no speedo calibration is needed. Basically you could (but I wouldn't lol) stick a 20" rim & a 30/35 series tire onto your car & have an unchanged total height.

If your combo DOES change the total height then, yes you probably will want to recalibrate your speedo etc

 

Thanks Grey.

At this point, I have the stocker 16" rims on my 97 GT. I think the tire height is like 55. I want to get some saleens that are 18" with a height of 35.

So as long as the total height of the tire is about the same, I shouldn't need any recalibration? Thanks.

 

yep. what greystang said. probably won't change enough to worry about if your overall diameter (tire and wheel assembled) stays within an inch of the stock diameter.