normally I agree with the by-the-numbers approach, but 10s of thousands of Jeeps are out there rocking 8" rims with the big fat tires, mine included. an 8" rim is just 1/2" off the typical "range "minimum". you may need to play with the air pressure to find that sweet spot for tire wear but you'll be doing that anyway since it's a giant tire under a lightweight Jeep.