Hi folks,

I own a 2007 H3X with 18" stock wheels. I believe they are 7.5" wide. It's time to get new tires and I would like to beef it up a bit. What is the largest tire size that these wheels will accomodate? I'm not looking for mud, just larger AT tires. I'm leaning towards BF Goodrich AT/KO. Thanks for the assistance!

 

Can anyone help with max tire size for the stock 18" x 7.5" rim on 2007 H3X?

 

I'm no tire whiz, but 18" x 7.5" is a bit different because when you go biger like 315/325s (35") tires, most want a wider rim as well.... some say 8" is the minimum. I did see some 33s that will fit, and I do not see any reason why you could not run 35s so long as you compare the outside actual diameter.

What I saw is most 35s for 16" wheels are a OD of 34.5 or 34.6", but when you go up to 18" wheels, a lot of the same MFGs are at an OD of 34.6 - 34.8. The larger of which might be pushing the envelope just a bit.

I would say look at 34.5-6" or so as your max actual OD tire diameter and you should be fine, most of those are also the same width as the 16" wheel sizes.

 

Thanks for the info. Maybe a situation where 305's make more sense, I'll have to take a close look at those dimensions. The Hummer folks maybe should've given the 18" rim an extra inch in width.

 

Just keep the diameter the same. That's can be a wider low profile tire.