I've run 7, 8, 9, 10. and 12" wide wheels in the past. 8" is by far my favorite. I didn't have failures with any of the other widths, but I have my reasons for not liking them.
Here are the reasons I run 8" wide wheels:
- I typically drive with 25 PSI MAX on any vehicle with big tires. The 8" width keeps the tread pattern wearing evenly
- you're a lot less likely to blow a bead on a narrower rim
- my wheeling style relies on using my sidewalls for grip/climbing. When I ran 10" wheels, my sidewalls didn't grip as well. They were shaped more like squares than balloons. This is especially true on KM2s. They have the lugs on the side, but with a 10" wheel, the lugs aren't the part that are sticking out the most. With an 8" wheel, it pulls the bead in closer, and leaves those lugs out for more grip. In fact, that's the reason I keep getting KM2s, those sidewalls grip like crazy.
- the valve stems are closer inboard so they're less likely to get ripped off by a rock.
- I like the look, but that's not important
- I can air down a lot lower without worrying about losing a bead. Pinches aren't a concern. If pinches are a problem, youre tires are too low-profile.
And here's why I choose steelies:
- they're cheap
- they're cheap
- they hold a bead better than aluminum
- steel wheels can be repaired when dented
- weird offsets are easier to get with steel wheels.
Disadvantages:
- steel wheels are heavier
- steel wheels don't balance as well
That being said, I always run steelies.