SVT 2007 Cobra rims and tire question

CBSTANG · 01-28-2007, 05:23 AM

I have posted this in the handling part of the 05+ forum, but didnâ€™t really get a good enough response, so if figured I would try my luck here. Anyway, I have finally made a choice on rims, I am going with the SVT 2007 Cobra rims. I found them at Tirerack.com, they are 18 x 9.5. I will be the first to admit that I know nothing about tires except that I do know that I want the BFGoodrich g-Force T/A KDW 2'sand Iam going with the same width throughout so that I can rotate them. Also tirerack recommended the tire size 255/45-18, I have no idea what they would look like,but basically I want the tires to look like the ones on this Roush, I only mean this by how tall the tire is compared to the rim(I hope that made sense). Also another big question is that I have the stock 17"s and I am pretty sure that when you change the rim and/or tire size you have to reflash the cpu to recalibrate speedometer. I am not quite sure how to do that and would appreciate help with this matter. I am very open to suggestions because as I said I have no idea at all when it comes to tire sizes.

[IMG]local://upfiles/24438/C8B462D4B9564E99BF732DF095BF4425.jpg[/IMG]

[IMG]local://upfiles/24438/2C32B24715504CFCAB2B18A0BD0316B0.jpg[/IMG]

CBSTANG · 01-31-2007, 11:56 AM

Nobody has any ideas?!?!

wingman75 · 01-31-2007, 12:33 PM

Quote:

ORIGINAL: CBSTANG

I have posted this in the handling part of the 05+ forum, but didnâ€™t really get a good enough response, so if figured I would try my luck here.Â* Anyway, I have finally made a choice on rims, I am going with the SVT 2007 Cobra rims.Â* I found them at Tirerack.com, they are 18 x 9.5.Â* I will be the first to admit that I know nothing about tires except that I do know that I want the BFGoodrich g-Force T/A KDW 2'sÂ*and IÂ*am going with the same width throughout so that I can rotate them.Â* Also tirerack recommended the tire size 255/45-18, I have no idea what they would look like,Â*but basically I want the tires to look like the ones on this Roush, I only mean this by how tall the tire is compared to the rimÂ*(I hope that made sense).Â* Also another big question is that I have the stock 17"s and I am pretty sure that when you change the rim and/or tire size you have to reflash the cpu to recalibrate speedometer.Â* I am not quite sure how to do that and would appreciate help with this matter. Â*I am very open to suggestions because as I said I have no idea at all when it comes to tire sizes.

Hey CBSTANG,

I can't figure out what you are asking in the first question. You need a reflash to set your new tire size. A Ford dealer could do it for you for a price. How much I don't know. Or you need to do it yourself with your own flash device, if you have one.

If you are asking about the tires aspect ratio here is what TireRack says.

Sidewall Aspect Ratio

Typically following the three digits identifying the tire's Section Width in millimeters is a two-digit number that identifies the tire's profile or aspect ratio.

P225/50R16 91S

The 50 indicates that this tire size's sidewall height (from rim to tread) is 50% of its section width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall; the lower the number, the lower the sidewall. We know that this tire size's section width is 225mm and that its section height is 50% of 225mm. By converting the 225mm to inches (225 / 25.4 = 8.86") and multiplying it by 50% (.50) we confirm that this tire size results in a tire section height of 4.43". If this tire were a P225/70R16 size, our calculation would confirm that the size would result in a section height of 6.20", approximately a 1.8-inch taller sidewall.

colin@tirerack · 01-31-2007, 12:37 PM

A 255/45-18 will have a sidewall that looks like the picture.

The overall diameter of the 255/45 tire is still within 3% of the original tire's diameter so your speedo etc will function normally.

CBSTANG · 01-31-2007, 05:40 PM

Ok great thank you thats all I needed.