I just put 20" American wheels on my 09 R/T. I have 245-45- 20's on the front and 255-45-20's on the rear. .
I still want to fill the rear wheel well more. How tall can I go and still not have any problems. One guy told me 275's are OK.
Can anyone help?
Thanks......New to this board

 

You're asking about tire diameter. "275s" refers to tire width. Without the aspect ratio (275/40, for example), you can't know what the diameter is. Taking the example as a starting point, a 275/40-20 happens to be virtually the same diameter as the standard 245/45-20. That's why they're a popular upgrade for the rear end. Apparently though, they won't suit your purpose of increasing the diameter. Sorry I can't help you on the maximum diameter that will fit, but it will depend somewhat on the width that you chose...