Need help with wheel offset

Will a 18x9 with +18mm offset fit on my 2017 wrangler Sahara unlimited at stock height without any rubbing issues?
Do I need a level kit or lift for these to fit?
If not what offset do I need to go with to fit at stock height?
Any information will be greatly appreciated. Thank you

 

I believe that +18mm offset on an 18x9in wheel is too much back space at 5.71"

0mm offset = 5"

I believe that you really don't want anymore than 4.75" backspace which is close to -8mm offset, but Richard, I believe will have more info on backspacing on a JK.

The size of the rim does not make a difference on the amount of lift you need. Bigger tires may require more lift.

 

Ok so 0 offset is my choice I would need. I using a 255/70/18 tire.

 

Is 255/70/18 the tire you have on your jeep now and you are wanting custom wheels for it?

 

4.75" of backspace is the most that you want. For an 18x9" wheel that equates to about a -8mm offset which I have never seen. A -12mm offset is roughly 4.5" of backspace and is what I would run if I were you. In the future if you wanted to go up to bigger tires the -12mm offset would allow you to do that without any tire rubbing on your control arms.

 

Yes 255/70/18 is the tire I have now and want aftermarket wheels for them.
Ok I'll will be looking for a 18x9 wheel with a -12mm offset.
Thank you for the help and info

 

Ok this was just told to me. Why is this the opposite from I've been told? I really need to be absolutely sure before I drop $1k or more on wheels.
Manufacturer recommends a +15 to +25 offset for your vehicle and this would allow you to run the stock tire size of 255/70R18.

 

Backspace is more important than offset. Maximum or minimum backspace measurement needed to fit a wheel and tire stays the same no matter how wide or what brand you choose. The Offset of a wheel will change based on different wheel sizes, and some manufacturers can differ in there backspace for the same offset (go figure). I just spoke to my buddy a manager at discount tire. To maintain a factory stance with 18x9 in wheels keeping factory tires you don't want to go more than 0mm offset. That is 5in of backspace. If you get an 18x9 in wheel and decide as most of us do that you want to run a 33 in tire then you will have to either buy new wheels to fit the tire, or buy spacers to fit them. When researching wheels and sizes you will notice that all manufacturers offer of backspace and offset measurements.

The +15 to +25 offset is true for a narrower wheel like the 18x8.5. Offset is measured in mm and is based on the center of the wheel.



Here is backspace in relation to the offset



Here is how to measure backspace.



The straight edge must be on the wheel not the tire. Take your wheel off and lay it face down on the ground. Take your backspace measurement. this is the max backspace that I would run. If you run a wider tire in the future you will need to accommodate this wider tire by running less backspace. I hope this makes things a little more clear.

 

Here is a picture of my JKU 4in lift on 37x12.50x17 tires with 17x9in wheels (same width as a 18x9in wheel). I have -12mm offset and 4.5in of backspace.

 

Ok choosing a 18x9 with 255/70 tire if I go with a -12 offset they will fit with no issue. Just stick out of the fenders? 0 offset will keep factory stance inside the fender. Is that correct? I really appreciate all your help and time you are giving me. I am truly greatful. Thank you

 

Sounds like you have the idea. As for actually sticking out of the fenders, I'm not sure about that. It is a half inch difference between 0 and -12mm offset. You may be still completely covered with your factory tires. Personally I like a little stickout. Looks tuff.

 

So, if I am ordering 18X8.5 rims and plan on sticking with the stock tire size of 255/70R18, will there be any problems? OFFGRIDs post makes me believe I should be ok but I am so confused with all the offset talk. Will my tires fit fine or will they stick out. I thought I understood the explanation on Tirerack.com that negative numbers equate to tires sticking out, positive numbers keep it tucked under the fenders. I would have liked a little sticking out but the rims I have been looking at do not offer them. If I am even understanding it correctly. I appreciate any help provided. Thanks.

 

Backspace will be the preferred measurement for this conversation, it remains constant no matter the wheel width. Offset will change depending on wheel width.

The factory wheel is 6.25" Backspace (BS), any stock size tire will fit without rubbing.
Once you go with a larger tire then you need to start adjusting the amount of BS.
33" tire around 5" BS
35" tire around 4.5" BS
37" tire around 3.5" BS

BS can be added with aftermarket wheels or by adding spacers. If adding spacers go with a quality brand, don't cheap out.

Tire width also plays into the equation, but the above measurements will work with most of the popular sizes.

Good luck and WELCOME!!

 

OMG, I was so geeked out to sign up and post I forgot to list the wheels have a 15 offset as listed from the web site for the size wheel I mentioned. Thanks again!

 

Welcome! You just received excellent information to order the right wheels. Be sure to post up some pics of that Altitude and new wheels

 

That comes out to 5.34" BS, you can use an online calc like this one: https://www.customwheeloffset.com/tire-wheel-backspacing-offset-calculators

So yes, you're good with those wheels so long as the bore and bolt pattern are in spec. It will stick out about 1" more than your stock tires/wheels.

 

BTW.
Welcome to the forum @17Sahara and @Plowking109.
Some awesome advice posted up for you guys. Would love to see some Jeep porn pics when your done with what you decide to do.