Originally Posted by CWilk
Why would I want less width on the wheel? And would it fit 12.5 wide tires? I go offroad quite a bit.
X2 on the 15x8 recommendation. First, that 12.5" wide tire isn't 12.5" wide anywhere but at its widest point which is half-way up its sidewall. Neither the tread nor bead seating edges are anywhere near that wide.
The benefit to a 15x8 wheel with a 33x12.50 tire, and I run 15x8 wheels with my 35x12.50 tires, is that you can air down to lower tire pressures with less chance of the tire coming unseated than with a 15x10 wheel. It makes sense if you think about that it takes less air pressure to hold a tire against two wheel edges that are 8" apart than if they are 10" apart.
The bottom line is you can offroad with less worry about your tires unseating with 15x8 wheels than if you went with 15x10 wheels. And a 15x8 works fine on the street too.
For backspacing, 3.75" to 4.5" is what you want. 4" to 4.25" is ideal. 4.5" is a tad too much but it works if you add two washers to the steering stop bolts. That's what I used to run since I didn't want my tires sticking out any further than necessary for some of the tight/narrow trails I enjoy.