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

Discussion in 'SVT Tech Forum' started by Ganton, Apr 4, 2005.

  1. I have 275 40 17 on the back and Im running sportline springs
     
  2. these were 12" wide and way to tall LOL
    [​IMG]
     
  3. 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.

     
  4. 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. :)
     
  5. 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.
     
  6. Cant really help you with pics of the car, since mines a 97, but heres a little comparasin between a 245 and a 275:

    View attachment 517879
    Yokohamas on the left (245) and NT555s on the right (275)
     
  7. They're ZR rated, and I got a pretty durned good buy, methinks...

    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
     
  8. 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.
     
  9. I'm 245X17 in front and 275X17 in back. Sits pretty good IMO.

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  10. Holy old thread resurrection Batman. :D
     
  11. lol. I just replied to the post as they pop up on my recent views. Never took the time to look at the beginning date of the thread. lol 6 months later. :D
     
  12. 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 ****in though.
    BTW Eibach ProKit also on mine[​IMG]
     
  13. I have pictures on SVT Talk with 255/50R17 tires on the rear (27.1 inches diam) with 275/40R17 fronts that are 25.7 diam. Car has H&R springs lowered 1.5". See item relating to Stance with rear tall tire.