I'm for sure going to buy 31x10.5 Duratracs, so what do people say? 15x7 or 15x8 wheel?

 

the smallest you can go on a 15x8 wheel is the 30x9.50x15 the next size tire down would need a 7.5" wheel

 

So 15x7 would be a lot better

 

right now ive got my 30x9.50 on a 15x8 wheel on trails i air down to 20 most of the time and no problems at all with it

 

I'll get the 15x7 inch rim then. I'm only running 31x10.5 duratracs, no larger. Cheaper that way, and I can go smaller tires if I need for some odd reason.

 

with a 31x10.50 when air down it will just bubble a little more

 

Bubble????

 

side wall pushes out a little more on the tire

 

Got it. Just did a little more research, and I guess mounting the tire on a thinner rim will also thin the actual width of the tire mounted on it, as opposed to mounting it on an 8 or 9" rim. I'm gonna spring the extra few bucks for the 15x8's.

 

Thats why companies have r&d these guys telling you they know best are just blowing hot air up your azz ( i think they like to do it) go by the specs.

 

Yeah, been on tirerack looking at the duratracs i'm buying, and it'll be fine on any rim between 7-9 inches, the measured rim width being 8.5.

 

also its not so much the height of the tire but the width is more important while selecting the right rim

 

Lol, yeah. That I knew. I was just saying that if the tire is mounted on a thinner rim, it will be pulled inward a little, and thin the tire width slightly. If mounted on a wider rim, the opposite effect will take place.

 

I work at a shop doing rims all day long. The rule of thumb i was always tought is that you only go 2 inchs wider then the rim. The main reason being that if you go to much wider then the rim you pinch the tire and increase the hight of the tire and can cause clerance problems

 

Someone has given you bad information. Most all tire manufactures recommend tire widths up to 4 inches over the rims width. The reason they don't go over 4 inches is because they use the 4 inch rule for all tires and rims not just our off highway tires.
An eight inch rim will work fine with a 12.5 inch tire. If you drive at speeds over 120 with your 12.50s you may need a 9 or 10 inch rim.
Mostly the recommended rim width has more to do with litigation than anything else.