Mounting tires rated for up to 8.5" rim on 9" rim

[08TRDOFFROAD]

I currently have a set of 17x9 rims that I want to mount some 265/70/17 BF Goodrich AT's on, but that size is only rated for up to a 8.5" wide rim. Will it cause problems to mount the tire anyway, realistically it is only stretching the side wall .25" farther than intended on each side? What do the experts think? (My local tire shop says they don't see a problem and will mount them...)

[Discount Tire]

Yes, actually it is an issue, great question. The short answer is "Just because you can, doesn't mean you should" but thats not enough for most people.

Here's a little more of the "Why not?"
Tires are designed to flex in certain areas when you mount a tire outside the tire manufacturer's recommendations you are forcing the tire to flex in areas where it is not designed to do so. This makes the tire hold more heat and heat is a tires worst enemy. The more heat a tire holds, the faster it will brake down and excessive heat can lead to tread separation or worse, a blow out. Also, most tires, all the brands we sell, come with a manufacturer's warranty for manufacturer defect and workmanship. When you mount a tire outside of the recommended rim widths, these warranties are void.

Hope this helps. You can probably find someone that will mount them for you but if you'd like to keep safe and get the most out of your tires, I wouldn't recommend it.

[08TRDOFFROAD]

Do you have any recommendations on a AT tire in 265/70/17 (load range C or D would be nice) that will perform well in snow that can safely be mounted on a 9" wide rim.

[Discount Tire]

Actually, It looks like the P265/70R17 Nitto Terragrappler is approved for a 9" wide wheel. The LT265/70R17E (10ply) is only approved for an 8.5" wide wheel max.

Here's a link to the P-metric size that is approved for a 9" wide wheel:

http://www.discounttiredirect.com/di...w=false&cs=265