255 75 17 stock rubicon tires and wheels question from noobie
 

I am clueless about tire sizes. I hear about 33's and 35's. How does my stock tire measure up to a 33? Will a 33 fit on my current wheel and stock suspension with out modifications? I'm sure this has been asked before! Thanks for the help. Any Seabrook Texas jeepers here?

33s will fit without any modification, but u might rub at full turn against your bumper,might need to spend a few bucks on spacers

How much bigger or taller is a 33 from my current setup? Are you talking about spring spacers? Would I need 1 inch or more? Also with monkeying with the suspension, will it cause the wobble problem?

Your OEM Rubicon tires are 255/75R-17, which means they are 255 mm wide, or 25.5 cm. 1 inch = 2.54 cm, so your tires are roughly 10" wide. The aspect ratio is 75, so the sidewall height of the tire is 75% as much as the width of the tire, or roughly 7.5". To get the overall height of the tire you add the diameter of the wheel to the height of the sidewall of the tire (both above and below the wheel). That makes for a tire that is 17" + 7.5" + 7.5" tall, or 32". So your 255/75R-17 tires are 10" wide and 32" tall. The stock Rubicon tires are actually very good tires by the way, better than the BFG KM2 tires are. Too bad they only come in the one size that is standard on a Rubicon.

The stock Rubicon tire size is 32" based on my calculations. A 33 should be 1 " taller. Some 33's are slightly taller or shorter though.

To calculate your tire size in inches, do the following:

255-75-17
255mm wide - 75% profile - 17" rim

1) Tire width (mm) multiplied by profile in decimal (ie: 75% would be 0.75). (255x0.75=191.25mm)
2) Value from step 1 multiplied 2 to give you the height of your sidewall above and below the rim. (191.25x2=382.5mm)
3) Value from step 2 divided by 25.4 to give you inches. (382.5/25.4=15.05")
4) Value from step 3 plus rim size (17" in this case). (15.05+17=32.05" overall tire height)

Oh yeah, first post, but I've been lingering for a while. Hello JK-Forum!

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A minute too late lol