just for discussions sake mine are 315/70/17s and they are 34 1/4 in''.

 

I went from the stock Bridgestone 32" to BFG A/T KO 315x70x17 and I could tell a big difference. Maybe not so much in the city but definitely on the highway. Dang JK wants to keep shifting down just to run her at 70mph. I could deal with it and just drive with overdrive off but I will be changing my gears before the end of the year.

 

I just broke down and spent the bucks to go 5.38s on my auto 07 after I got my 35s. Running procomp xterrains. I think they were 34.75 if I remember right.
I have not done any speedo calibration yet but the gears made a huge difference. Don't waste your time with 4.88s.
I can't even imagine driving with 3.73s and 35s. I had 4.10s and it was terrible.

 

We must also, consider how each JK is built also. After market bumpers, winch, gear, etc. all squish down the diameter of the tire, as does the air pressure at which we run at!

 

X2. I'm in the same boat. Not for long!!!

 

My tires are i think 34 and a half their "Nitto Terragrapplers oh and a rough country lift 3.5" lift
i like them alot!!! the jeep is fairly quick but i have the volare snorkel cold air intake and thats it