New size tires for my '01 Cobra? Need opinions.

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these were 12" wide and way to tall LOL
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There are alot of tires out there at 255x40. I wasnt aware of any major diameter differences between tires of varying widths. The overall diameter difference between Kumho 245 and 255 is .3" which isnt much and would have little affect on the speedo. Now regarding profile of the tire, the over all difference between Kumho 245x40 and 245x45 is 1.1" which would affect the speedo. Either way I program my own EEC using SCT according to the exact tire sizes I am running so it doesnt affect me at all.

hersheyman said:
I didn't think that anyone made a 255/40, only a 255/45. Either way changing to a 255 will throw off your speedo a little, so just be aware. I just purchased new wheels and rear tires for my 97 a couple weeks ago. I kept the 245s up front cause I think they fill the well fine and don't mess up the speedo. But I put real meat out back on 10.5" wheels. Check it out.
 
Got em on there.

Okay, I went and did it. 255/40s up front and 275/40s out back on the stock 17 inch rims. Like one of you said, above, there is more sidewall bulge with the 275s on the stock 17" rims, but it doesn't look that bad to me at all---maybe it's the sidewall design of these tires that minimizes it? They're Falken ziex ZE 326s, probably not up to a lot of the tires seen on this forum, but the price was right and they got a high speed rating, VR or maybe ZR, dunno for sure, will have to look. They are a good looking performance tire, and look a lot like the ones on SnakeCharmer's convert. in profile and design. I'm a little disappointed in that the 255/40s up front increased the wheel well gap somewhat from the 245/45s, but the big 275s in the rear fill it up good. Seems like the car has a bit more quickness on initial acceleration, maybe due to the the wider rubber in the back, or is that just my imagination and wishful thinking?? Overall, I'm real happy with the ride and improved handling. :)
 
Ganton, congrats. an FYI, as I noted above about the .7" difference in diameter between 255 and 275, if you use a chip or other to compensate for the speedo base the chip settings off the rear 275's. That is where the EEC reads from regarding the speedo calculations.
 
They're ZR rated, and I got a pretty durned good buy, methinks...

Ganton said:
Okay, I went and did it. 255/40s up front and 275/40s out back on the stock 17 inch rims. Like one of you said, above, there is more sidewall bulge with the 275s on the stock 17" rims, but it doesn't look that bad to me at all---maybe it's the sidewall design of these tires that minimizes it? They're Falken ziex ZE 326s, probably not up to a lot of the tires seen on this forum, but the price was right and they got a high speed rating, VR or maybe ZR, dunno for sure, will have to look. They are a good looking performance tire, and look a lot like the ones on SnakeCharmer's convert. in profile and design. I'm a little disappointed in that the 255/40s up front increased the wheel well gap somewhat from the 245/45s, but the big 275s in the rear fill it up good. Seems like the car has a bit more quickness on initial acceleration, maybe due to the the wider rubber in the back, or is that just my imagination and wishful thinking?? Overall, I'm real happy with the ride and improved handling. :)

Just thought I'd add as a closing post in this thread that these new Falken ZIEX's are ZR speed rated. Also, the 255/40s were $127.13 a piece and the 275/40s were $158.98 for a total "out-the-door" mounted, stems, spin balanced, and state sales tax of 8% of $663.65 (they happened to be "on sale"), which I thought was a pretty durned good buy from a "brick 'n mortar" tire, brakes, suspension chain store rather than a magazine or online "tire rack outlet." :D
 
I put 275/40 on the stock 8 inch rims on the front and 255/50R17 on the rear which are 1.4 inches taller than the 275's with 1 inch spacers and lowered 1.5 inches. This puts gives the car that ol muscle car rake and fills the wheel wells.
 
18" X 9" front wheels, 265/35
18" X 10" rear wheels, 285/35
What I would do next time:
17" X 8" front wheels, 255/40
17" X 10.5 rear wheels, 285/40
Why? too harsh of a ride and tracking from the front, it sure looks bitchin though.
BTW Eibach ProKit also on mine
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