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Discussion Starter · #1 ·
I am in the market for new wheels for my '97 TJ, and was going down the path looking for 15x10" wheels I have now. I think the backspacing is around 4.5". I intend verifying before purchasing either way.
I saw some posts stating 8 inchers will work just as well, if not better, especially when on the trail. My Jeep is not a trail master and I do go off-road occasionally but most miles are on the pavement.

I am running Cooper ST MAXX 15x12.5's.
The current setup does not rub (4"inch lift) and doesn't extend out too bad.

1. Will 8 inch width wheels work safely and also not cause the tire to wear unevenly?

2. If 8 inchers are okay, what backspacing would I need to make clearance but yet keep the tires as far under the Jeep as possible?

Thanks for any input.
K
 

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A 15x8 is preferred for a 33x12.50 or 35x12.50 if you air down much for offroading. I've been running nothing but 15x8 for 20 years for that reason. Tire wear is no different on a 15x8 vs. a 15x10 with proper tire inflation.

You'll want 3.75 to 4" of backspacing for a 12.5" wide tire. You could also go to as much as 4.5" of backspacing but you'd need to add a couple small washers under both steering stop bolts to stop tire rub at full turn-lock.
 

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Discussion Starter · #3 ·
Jerry,
Let's assume I have 4.5 backspacing now on the 10" wheels.
If downsizing to an 8", the same backspacing will not work? I should go to a 4.25 or 4? Without having to use the washer scenario.
 

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What size tires are you running? You only say 15x12.50 which does not include their diameter. I'd be surprised if you're not getting tire rub with 33x12.50 or 35x12.50 tires with 4.5" of backspacing when the steering wheel is turned all the way left or right unless perhaps a previous owner installed the washers I mentioned above onto the steering stop bolts.

I ran 4.5" of BS for several years with 35x12.50 tires without problem but I had to add those washers.
 

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Discussion Starter · #5 ·
I saw I left that out. Have yet to find the edit button!
35x12.5x15. And no rubbing. Perhaps the backspacing on my current wheels is 4"? That needs to be my starting point I understand.
 

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From Coopers website, for the 35x12.50x15 they recommend 8.5"-11" rims. and prefer 10" rims.

Not that you cannot pick something outside that range but you may have warranty issues if you chose to ignore their recommendations.
 

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I've never seen a manufacturer recommend 8" rims for a 12 inch tire. If you see a lot of highway miles I would look into the recommended tire width, find out why and then make your decision. I don't like to break rules until I know and understand them, regardless if "everybody" does it. It has been a few years since I searched exhaustively to see if any manufacturer made a 8" rim recommendation for a 12 inch tire, so someone may have done it since then.
 

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Jeep doesn't recommend 35" tires and manufacturers of 35" tires don't recommend airing them down to single digit air pressures either as we do. 10" wide wheels are not recommended for 12.5“ wide tires for those who air their tires down for offroading. Only an inexperienced Jeeper would recommend a 10" wide wheel for that size tire to someone who offroads and airs down.
 

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Most tire manufacturers will err way to the conservative side due to the litigative nature of everyone and keeping the company lawyers happy. The fact is that the Jeep community as well as other 4 wheelers have been running 12.5" tires on 8" rims for years without issues. As mentioned above, an aired down 12.5" tire will hold a bead much better on an 8" rim than it will on a 10" rim, and will be fine on the the road as well.
 

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i've never seen a manufacturer recommend 8" rims for a 12 inch tire. If you see a lot of highway miles i would look into the recommended tire width, find out why and then make your decision. I don't like to break rules until i know and understand them, regardless if "everybody" does it. It has been a few years since i searched exhaustively to see if any manufacturer made a 8" rim recommendation for a 12 inch tire, so someone may have done it since then.
blah blah blah.
 

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I've never seen a manufacturer recommend 8" rims for a 12 inch tire. If you see a lot of highway miles I would look into the recommended tire width, find out why and then make your decision. I don't like to break rules until I know and understand them, regardless if "everybody" does it. It has been a few years since I searched exhaustively to see if any manufacturer made a 8" rim recommendation for a 12 inch tire, so someone may have done it since then.

You will find no recommendation from Jeep to run 33 or 35 inch tires, if you look on the decal on the door post, neither tire size is listed as acceptable or in the owner's manual

Nonetheless, the 8 inch rim is far superior on a Jeep Wrangler for the 33 and 35X12.5 tires. There is no unusual wear, you can air down more, it looks better and in all ways works better and in no way is dangerous. Assuming you go against the manufacturers recommendation and upsize to 33/35 inch tires on your jeep Wrangler.

J
 

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You will find no recommendation from Jeep to run 33 or 35 inch tires, if you look on the decal on the door post, neither tire size is listed as acceptable or in the owner's manual

Nonetheless, the 8 inch rim is far superior on a Jeep Wrangler for the 33 and 35X12.5 tires. There is no unusual wear, you can air down more, it looks better and in all ways works better and in no way is dangerous. Assuming you go against the manufacturers recommendation and upsize to 33/35 inch tires on your jeep Wrangler.

J
I was talking about tire manufacturers recommendations, not jeep recommendations. If the OP is doing a lot of highway driving it may, and probably will affect warranties. That is kind of important to know.
 

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I run 33x12.5x15 Goodyear MT/R's on my stock Jeep Ravine 15x8 wheels, no problems. On road, off road or at highway speeds. I do run 1.5" Synergy wheel spacers to keep from rubbing.
 

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I was talking about tire manufacturers recommendations, not jeep recommendations. If the OP is doing a lot of highway driving it may, and probably will affect warranties. That is kind of important to know.
You should use 10 inch wheels. The OP should use 8 inch as there is no downside.

J
 

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I was talking about tire manufacturers recommendations, not jeep recommendations. If the OP is doing a lot of highway driving it may, and probably will affect warranties. That is kind of important to know.
If a tire shop mounted them, they will warranty them.
 

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10" wide wheels are not recommended for 12.5“ wide tires for those who air their tires down for offroading. Only an inexperienced Jeeper would recommend a 10" wide wheel for that size tire to someone who offroads and airs down.
"My Jeep is not a trail master and I do go off-road occasionally but most miles are on the pavement."

Some of us actually read what the OP says...
Try taking a reading comprehension course.
 

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"My Jeep is not a trail master and I do go off-road occasionally but most miles are on the pavement."

Some of us actually read what the OP says...
Try taking a reading comprehension course.
Your snide/uncalled for remark aside, I did of course read that and the vast majority of us drive way more miles on the highway than we do offroad, me included. My recommendation for the 8" wheel stands as there is no practical downside to using 8" wheels but there's a lot of upside to using that width wheel offroad. And I've yet to have any tire warranty issues from using 8" wheels in my 20 years of using 8" wheels on Wranglers. Not to mention most 8" wheels are 8.5" which is in the 8.5-11" range that is recommended for the 12.5" wide tires I am aware of. My Walker Evans wheels are 8.5" in reality though they are just commonly referred to as 8".
 

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"My Jeep is not a trail master and I do go off-road occasionally but most miles are on the pavement."

Some of us actually read what the OP says...
Try taking a reading comprehension course.
We all drive mostly on the road, DD, though I also drive my Taco. I drove my Rubie to Key West last summer from Kansaw, summer before Nevada, this year I am heading north to Montana. My Jeep rolls on 8 inch MT wheels and BFJ 33X15X12.5 tires and I have no balance, unusual wear or other issues with the 8 inch wheels nor did I on previous installations (on Toy trucks).

I had 35 inch MT Crusher tires on 8 inch, but I went down to 33s, for fuel economy and general driveability but the 35s did fine on the 8 inch wheels. This photo shows my tread pretty good, about 15,000 mostly highway driving, very even wear, running about 26 to 28 psi:

 

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You should use 10 inch wheels. The OP should use 8 inch as there is no downside.

J
The OP should make his own decision, preferably after being properly informed by folks like you with experience, and after being told of manufacturers recommendations. That way, when something goes wrong, he can take responsibility when lawyers prevail in a ridiculous argument that the use of equipment for an unintended purpose caused somebody a loss; and more lawyers get ridiculous laws passed putting and end to what we love doing

No one should be giving anybody crap for informing a member that, on paper, a common usage happens to not be a recommended usage.

I don't care what he does, but I do care that he knows what he is doing.
 
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