[TXST8tj]

a 12.5" wide tire is ok on a stock/7" wheel....it's not the best, but the real issue is the backspacing of stock wheels. a 12.5" tire on the stock rims will rub badly. you would need wheel spacers to run that setup, and you can sometimes run new wheels for the cost of spacers.

 

[mrbigjeep]

like said you'd need spacers. plus its better to keep the tire width within 4" of the rim width. (i.e. no less than a 8" wide wheel on a 12.50" wide tire) an 8" wide wheel will mount on a 12.50" wide tire fine and will hold the bead a lot better.

 

[nicolas-eric]

i have a 32x11.5 tires on a 7.5x15 wheel.

off the road it´s pretty good because the tire doesn´t come off the wheel with low pressure.
on the road it isn´t as good because with the right tire pressure the tires have only road-contact at their milddle.
reducing the pressure to the point when they have full contact to the road the handling of the tj is very bad.

my next tires will be 33x12.5 on 10x15 wheels. it´s my daily driver and good on-road capabilities are important for me.

for off-road use i would prefer between 7x15 and 8x15 with the 33x12.5 tires

 

[affende]

i run 33 x 1250 on an 8 in rim with no problem (4.00 backspacing though ... as stated you will have problems with rubbing on a stock backspaced rim)

i run 37 x 1650 on my toyota with 8 " rim ... again as state, rubbing is the problem, not the width of the rim.