Nice forum guys, I used to drive a ford ranger and frequented therangerstation quite a bit and found it to be helpfull over the years. Hopefully I'll have the same experience here. I've searched around but haven't found exactly what I'm looking for. Here is my question. My colorado is a 2005 4 door with the Z71 package. Right now it has 265 75 15's on it. I am wondering if I can go any bigger without doing any modifications. I just want to go a LITTLE bit bigger, maybe one size. How does say a 31X10.5X15 compare? Any suggestions would sure be appreciated.