What is the biggest possible tire I can go on my truck without a lift or leveling it.
12 stx 4x4
5.0

 

33" probably. Don't go too wide either unless you want spacers.

 

I had 285/70/17 on my truck with no lift or level for a while with no running at all.

 

I just replaced my 275/65/18's with 275/70/18's with no rubbing at all and I have not lifted or leveled the truck at all. In fact I've got a good 3/4" of clearance left when the wheel is cranked over as far as it will go. I also bumped up to E load tires (10 ply) and can not feel much difference over the factory original tires. I put Cooper Disvoverer RTX on and they look good.