True, you can do it but just because you can doesn't mean you should.

Running a wide tire like that on a narrow rim leads to crowning unless you run at a low psi to get a correct contact patch, which is detrimental to mileage and leads to increased emissions leading down that slippery slope to having your local brown shirt eco nazis knocking on your door, leading to...

Sorry, couldn't help myself.

 

You will be fine with that wheel and tire combo.

 

Really leads to poor wear with 12.50 wide tire and running a 7.5 to 8" wide Rim??? I got near 60K miles on the FC-II's on my diesel with normal tread wear and rotated every 5-6K miles.

I got near 27K miles on my Cooper STT's on my Wrangler and they still have 2/3 to 3/4 tread life and are wearing normal and rotating all 5 approx. every 5K miles.

The only thing you will see running a wide 12.50 tire on a narrow rim is the sidewalls will bulge out more...I have had no issues with tread contact on the pavement or off-road conditions. Also, with a narrower rim it will keep a bead better than a wider rim when you are running lower PSI off-roading.

 

You will be fine with that trire size on that rim. IMHO i would look at a different tire anyway. I have the BFG's on my F250 and hate them. I have had them about 10k miles and they can not be balanced, they ride rough and if the PSI gets off a little it is even worse. My dad also has tehm on his F350 and has the same complaints. Just my experience i am sure alot of people have had good experience with them. Go for the Toyo Mt's

 

i'm running 12.50 pro comp mud terrians on my stock rubi rims with rough country spacers. i've had no problem with mine as of yet. and i prefer it this way offroad

 

you won't have to worry to much about the bead comming off

 

There are a couple things in play here. Many people on this forum and other for off road use will use a narrower wheel width than recommended to prevent rock rash and hold the bead better aired down. It works for them and what they are giving up is some road handling characteristics and heating up the bead at highway speeds. I see no particular reason for crowning, just a need to run at lower pressures to keep the contact patch evenly planted.

Then there are the group who choose wider wheel widths. The advantage is better on road handling, higher inflation rates and better fuel mileage. There also isn't the same stress placed on the bead. The disadvantage is a wider rim prevents you from airing down as much off road and on road the higher inflation rates can give up some ride quality.

Nothing wrong with either, and much to do with personal preference. For me, I prefer to stay within the manufacturers recommended wheel widths, although on the narrow side. I'm not nearly as concerned about having a tire issue off road as I am on it, with a high COG vehicle at highway speeds. So when I look to the experts on the subject, I tend to go with the manufacturer who seemingly all have a recommended range of wheel widths.

 

Has anyone had any personal experience with the Wrangler DuraTracs? Cause I was also looking at those which is about a half inch narrower so that makes me feel better as well. A lot of reviews on the tire is that they are great in mud and snow/rain compared to most AT or MT that are horrible in snow/rain. Noise is apparently good but the only thing I have yet to find is someone with over 15k miles on em to tell me how the wear is.

 

I disagree on the comment about not being able to air down as much with the wider wheels.

For many years, I ran 33x12.5-15, then 35x12.5-15 on a 10" wide wheel on my CJ. I would routinely air down to 5-6 psi and NEVER popped a bead. The only time I popped a bead was when I ran some 33x14.5-15 on those 10" wheels at 5-6 psi.

So, no problems when I was in the 2-3" range as suggested by industy experts. My problems arose when I went outside that range which I did with the 14.5 wide tires on the 10" wheel, which is equivalent to a 12.5 tire on a 8" wheel.

So, I'll stick with what the industry experts say.

 

The volume of air is different on the same size tire when mounted on different wheel widths. When rolling over an obstacle that lessens the weight bearing contact patch size, a tire with a lower volume of air will need to deflect less to increase the pressure to be supported on the contact patch.