255/85r16 question

Hey yall looking at getting some new tires soon (255/85r16), and was looking at the ST maxx and km2 and noticed that the ST Maxx are listed at 32.8" and the KM2 as listed at 33.3". to me that seems like a pretty big difference for tires that are supposed to be the same. i have Cooper AT3 right now and have loved them so i really want to stay with them but wasn't sure if any of you guys had run both and felt strongly one way or another.

 

yea the measurements above are from each manufactures website, i guess i was just surprised at just how much of variance exists.

 

Gotcha. Still think im going to go with the coopers after reading all good reviews on here about them