The title pretty much says it all.
I'm planning on getting some 33 x 12.5 BFG T/A KO's and I was wondering if I can have them squeezed onto the stock 15x7 rims?
I'd rather not have to buy new rims but if need be, I will.

 

This question has been asked & answered several times in the past, but I could see it being a hard one to search for.

The answer is yes, but you could have trouble finding a shop to mount them and you will also have to run a lower tire pressure to keep the tread wear uniform.

 

i did this on my 4runner and had no problems i actually liked the 15x7s better than the 15x10s i got now cuz i could run a lower psi when wheelin and not worry bout popping the bead off

 

The manufacturer usually recomends an 8" to 10" rim width for a 12.5" tire. Like the others said it can be done, and many are doing it. I myself am doing it. There are a few drawbacks...

- Lower tire pressure to maintain a flatter footprint = Poorer gas milage, and on these trucks it sucks to start with.

- Heavy compaired to a 9.5" or 10.5" tire = Poorer acceleration (unless geared to match) on top of the already poor acceleration, also affects braking, (marginally over narrower 33's)

- Rubbing is increased due to the extra width of the tire with no extra backspacing, (but increased backspacing also increases the arc of the tire when turning and this also increases tire contact with the fender and frame)

Here is a picture just to show you how it would look...