I just bought an 08 srt8 a few days ago and it came with 255 all around. I would like to keep the 255 for the front but would also like to get the largest tire in the back. Whats the fattest tire that also fills up the wheel well the most in the back? with the stock srt rims of course, thanks !
You can go 275-285 on that wheel...for example I'm running 315 on a 20x10 and that def is not recommended by the tire calculator but it def DOES work....
some in here did a 315/35/20 with the stock rims. It looks a bit funny with the bulge but it works too if you get nittos (the run smaller).
I wouldn't drive them hard though
I would go no wider than a 275 on the stock 9" rim. If the tire is too wide for the wheel, its load capacity will be adversely affected, as well as its contact patch control because of the excessive sidewall roll over.
This will put the sidewall under extreme stress which can cause several things to happen:
1.) catastrophic sidewall failure due to load issues.
2.) complete tire failure due to excessive heat being generated by additional flex and/or roll of the sidewall.
3.) adversely effected handling since the sidewalls can not control the contact area properly.
4.) breaking of the tire bead area under extreme cornering causing immediate loss of air pressure and vehicular control.
I am Running Mickey Thompson ET Streets in 305/30/20 on my Factory Challenger rims without spacers as well. A little snug on the inside of wheel well. They rub when car is on stands, but back on the ground there is 1/4" of room between plastic inner fenders and sidewall.