Need Help Understanding Wheel And Tire Sizes.

[cghbuilder86]

I've been looking on the websites for some new rims. When I put in what model truck I have it always brings up a list of tire sizes that will work with that trucks wheel size, and various size wheels. The stock wheels on my truck are 17x7.5. I want to stick with my original tire size (265-70-17) to be sure nothing is altered like mpgs, speedo etc. Plus these tires still have a lot of life left and I want to wear them out before replacing them. But it seems like the closest wheel size I can find is 17x9. Why is that? Shouldn't I get the 17x7.5? I want to be sure my speedometer stays right on and the outer size of the tire doesn't change. Wouldn't going to a wider wheel make the overall outer diameter of the mounted tire a little smaller? Also will any of this affect towing? Any wheel will be able to handle the rating of the tire correct?

[Superperv23]

The reason you mainly find 17x9 is that people usually run wider tires, say a 285, when they go with after market wheels, you will be able to find some that a narrower but just maybe not in the style you want. You will be able to run 265 on a 9in wide wheel and not see much of a difference in height as it is still an acceptable width for that tire. As far as wheel width impact on tire height, it does have some slight effect but not much in a normal width range. What a wider rim does impact is the handling and ride characteristics of the tire as the wider wheel the tire sidewall is less bulged and that makes it a bit stiffer,

[cghbuilder86]

okay thanks man, thats all good info. So I guess if I ran a 17x8 instead of a 17x7.5 I probably wouldn't be able to detect any difference. Because I have seen some 8 inch wides that I like but I don't think the first 7.5 wide. Also what is all this about offset? I'm in the dark on that.