Need help please, I have a 04 Cobra with factory wheels and need to know the widest rubber I can install. Or should I buy different rims??
Thanks Slang.
It depends on what brand/type of tire you want to run. 315 works for Nitto 555R drag radials, but others say no. The limiting factor seems to be the upper IRS subframe bolts. They stick out. You can grind them down for more clearance or buy MM bolts that are rounded so if they rub, it won't hurt anything. Then you can even run 10.5 inch wheels, so some say.
Mac
If you are talking about the widest tire on the stock rim... tlrdynes is correct. A 315 Nitto will fit on the stock rim without rubbing, but ONLY the Nitto 315. Any other 315 will not fit without bulging too much or rubbing. For some reason Nitto tires are more narrow than all others.
If you move up to a 10.5 inch rim then you will have to look into spacers, replacing IRS bolts, or at least grinding the stock bolts. It all boils down to what size rim you use and what brand of tire.