Does anyone running 31-35 size tire on OEM 17 alloy wheels? Any recommendations would be greatly appreciated.

 

Yes some even run 37's.
You will need 1.5" spacers if your running 35's though

 

I'm thinking about replacing my 255/75/17 with a 315/70/17. Will that fit on my OEM 17 alloy? And do you think I still need a spacer for that?

 

You will need a spacer. I run 315/70/17 on wheels with 4.5" of back space (I think stock is 6.5"?) and I still had a rub issue - and have a 2.5" lift.

I did similar research as you and the takeaway is that the tires will fit on stock wheels, but for daily driving, are not ideal. The tire manufacturer guidelines are generally for a min rim width of 8.5" vs. the 7.5" you have now. Many will say it is a benefit off-road to run the narrow rim, which I suspect is true. That said, it is my understanding that for on road driving, it is not ideal. I figure the tire manufacturers have some clue as to what works and what doesn't. While an inch doesn't sound like much, in this case your rim width is almost 15% below the min recommendation.

 

Thanks for your help.

 

Stock 17" rims are 7.5" wide.
According to the tire calculator I use, a 317/70/17 tire should be on no less than 8.5" wide rims, but I'm sure that lots of JKs are running this size on stock. Whether it's a good idea or not is not for me to say....

 

yeah you'll want 1.5" + spacers. I run 315/70/17's on my OE Grand Cherokee wheels, same size specs as wrangler wheels 17x7.5". I have 1.75" spacers, and still get some minor rub on my lower control arms at full turn, no biggie though.

 

You got a pic of those Cherokee wheels on your wrangler?