How much will my speedo be off?

[5LiterFever]

This week I will be taking the stock 16" wheels with 225/55 tires off my 95 GT and replacing them with 17" wheels (stock 98 cobra wheels) with 245/45's. How much will my speedometer be off by? Stock gears btw.

 

[rio95]

those are the same outside diameter (pretty close), so it won't be off. i used to have 16" waffles and now i have 17" and i never had any prob. with the speedometer.

 

[Ryan Paterick]

When you switch to 3:73's, Oh yes you will! Your speedo will be way off. I've heard either get the 23 tooth speedo gear or a SpeedCal.

BTW, love the color scheme on the car.

 

[jmuva44]

yeah I think that those two tires will be the exact same diameter so everything will stay the same.

 

[rio95]

i don't see him talking about 3.73's anywhere??????????????????? he's just talking about tires.

 

[Ryan Paterick]

i don't see him talking about 3.73's anywhere??????????????????? he's just talking about tires.

I know, I just put that in there so he didn't have to ask when he put in new gears.