just wondering if I need to recalibrate for my new rims and tires?

 

How big of a change did you make in the OD of the tire and wheel?

 

well i went from stock 15 to 17
front tires are 275 back tires are 315

 

Yea, measure your diameter of your rear tire and divide that into 20168 Tire revs per mile
20168 divided by 26" = 775

 

Not sure, but maybe this will help.
http://www.americanmuscle.com/99-04-tire-sizes.html

 

I do know, that the tires you got are the same sidewall height as a 245/45 17..

Which came on GT's, Mach1's and Cobras.

But i cant remember stock v6 sizes.

 

well I have the predator wont that do it for me?

 

Your old tires and new tires are withing spitting distance of being identical as far as overall height. You'll be fine without any changes. Don't worry about unless you get stupid with the tire sizes. You'll know... it'll rub.

 

ok, maybe its just me but it seems to me that im going faster than my speedo says.

Got the same ones are you red

 

I highly doubt your going that much faster if any. If you're not sure just have some one pace you on a highway, then you will know how fast you are going.

 

Just for ***** and giggles, measure your tire height and use your Predator to check it. Its takes 5 mins.

 

My cars 3 - 4 mph off.

I have 18s with 275 40s and 255/45. I think on the front.

And its off and I get occassional rub.

Just wish they would hurry up n wear so i can get wider and skinnier.

 

315, that's a big tire!

 

Na. I wish I had that.
My 275 isn't cutting it. haha