I'm running a stock 2013 JKU with factory rims / tires of 255/70/18. I'm looking into a larger tire size with smaller rims, such as 16's. Looking at 285/75/16 or 305/70/16. Back spacing will be 4.5" or under.

Will 33 x 11.5 or 12" tires require any steering or suspension mods?

Is there enough room to down size my rims and still have caliper clearance?

Any help from other JK owners is greatly appreciated. I'm sure I'll be coming into contact with my fenders while off-roading. Lifting my Jk and disco sway bars will be my next purchase.

 

Do have to go that much wider? I put 33x10.5r15 on my 13 jk. Downsides to this is your selection of both wheel and tire is minimal. Pretty much only get bfg at KO or km2 (I think) Its my DD and don't wheel nasty enough or offer enough so I got AT.

You'll need at least level kit or trimmed fenders. Won't have any steering issues BC most 15's that fit without grinding are 3.75 backspace. DTD is a great resource for this.

FWIW I went from 225\75 r16 with auto, 3.73 and AVG MPG is identical after 2k miles. City went down a tad and hwy up to offset. I DID notice a difference in butt dyno but still feels really good. Better than the wife's '14 civic.

 

Thanks for the reply! /cheers. I plan on lifting my jeep and like to have wider tires. After doing more homework on tire / wheel size and selections, 15" has caught my attention. 33x12.50x15 to be exact. The overall plan is to replace the stock parts needed for off roading and trailing. I'm also running 3.73 gear ratio and guessing I'll need to redo when I put 35" on it after other mods.

 

Just a note. If you ever want to upgrade to bigger brake rotors you will need at least 17" wheels......

 

33s with stock suspension will work just fine. 16" wheels will work just fine with your OEM brakes.

I had 33s on my JKU while waiting on all my suspension components to come in:


Limits flex, but mild offroading is still possible.

If you go 15s, just know that you may need some caliper grinding in order to fit them. Typically, all the 1-piece aluminum wheels should fit just fine. It's the 2-piece steelies that are hit or miss. This is due to their design. The 1-piece aluminum wheels are call cast from the same mold, but the 2-piece steelies are just that, two separate pieces formed together into one wheel. The very nature of their design means that tolerances aren't as tight as they are a 1-piece cast aluminum wheel. So, even across the same exact size and model wheel, 4 of them may fit while your spare won't.

 

mine are 285 70 16 i think they are 11.5 wide even still love them . no issues no rubs perfect for my need. 10 ply rated e so strong as nails nitto trail grappler. Also worth mentioning i think synergy tie rods have issue with 15" wheels too but not 100% sure . If you plan on upgrading things in future tie rod usually gets replaced with a better one such as synergy chromemoly style could be a speed bump

 

A 4.5" backspace is the usual recommendation for 35x12.50's. If you are going with 33's, you shouldn't have problems with contact on the frame/arms/etc. But, when disconnected/turning?

For 15's, you want an even lower backspace. Some people have been ok with 4", but 3.75" or lower seems to be the general recommendation. DTD has a big info thread on this where they suggest alloy instead of steel, and which also includes a list of rims they guarantee will fit without rubbing.

https://www.jk-forum.com/forums/spon...wheels-120933/

As noted, both 15's and 16's can also have clearance issues with the rod ends of many aftermarket steering components, and with all of the aftermarket brake upgrade kits. And if you have plans for larger tires in the future, there is a much smaller choice of tires available in the 37" and larger sizes. (for 16" 37's, I found 6 choices. These included a bias tire, which was not an option. Directional, which was not an option. Sticky offroad tread, not needed/wanted. And $400+ per tire, which definitely was not wanted. So in the end, I was left with 'two' actual choices to decide between... )

 

33s will rub with stock flares without adding increased bumpstops when disconnected. You'll also rub on the rear flares too.





That is a 305/65R17. Same as a 305/70R16

Sent from some string and a few tin cans.

 

It's looking like I'm going with 305/65/17. Doing a rancho 2" sport lift and removing the air dam. I believe there shouldn't be any other rubbing unless im disconnected. Flat flares coming soon.