What is the biggest tires for stock wheels?

I need to replace my falulty Firestone tires on my 97 XLT. I would like to go from the 235/70/r15 to a slightly wider tire. What is the widest tire that will fit on the factory 15" rim? I've seen some eddie bauers with 255/70/r15's, but I don't know if they come with bigger whels from the factory. Thanks for the help.

 

[ExplorGM]

15x7 or 15x6?

The width and offset and backspacing will determine the widest tire that you can fit. Probably an 11.5" tire if you have 15x7s. 10.5" would probably be the limit without a lift. My 16x7s came with 255/70-16s. Nice width, but I wanted more height.
Rick

 

[Turner55]

when i changed my tires i switched from 235/75/15R(or whatever the stock size is) to 255/70/15...they're about an 1" wider than stock...i think they look better