You live in Illinois, I'd go for the 10.5" width for the reason given by TheBoogieman. A narrower tire can dig down through several inches of snow more easily to the better traction of the pavement below. That is why tall skinny "pizza cutter" tires are popular in heavy snow areas for street use. A wide tire is only better on snow when it's DEEP like when you're offroad.
And X2 on what Wheelin98TJ says, no Jeep deserves the indignity of being made to run Rockstar wheels. To me, Rockstar's line of wheels are more suitable for pimpmobiles.
Alright I was planning on getting the 17x9 rockstars. Do you know if 12.5 will work for these
So the only issue with going with 17s is that the 33" equivalent size tire in a 17" rim size has a higher load rating. Which is not a huge deal except that with thicker sidewalks you are going to get a harsher ride....which over the long haul can get very annoying.
The ideal tire rim combo is 33x10.5x15 or 33x12.5x15. That's why you see so many people running them it's a tire that is made for our jeeps weight. I spent a ton of time researching this and narrowed it down to 2 tire brands for best value for money. If you're in a climate where you might see temps get below freezing then I would go Goodyear wrangler duratracs and if not them bfg km2
One more thing to consider is tire weight. Every 1lb on your tires is like 8lbs in your truck. So go to tire rack and check tire weights, you will find that the higher load rating tires are much heavier. Throw that on a large and wide rim and you are going to see acceleration and braking noticeably affected. Just a thought.
About the rockstar. I think they look decent. Don't listen to the haters...unless you're going for major chrome or spinners, then you deserve it. Lol
If you actually wheel the jeep I would go with 12.5. If it's really only street stick with 10.5 as suggested for snow.
I've personally never had an issue with 12.5" wide tires on the street in snow. Ice however is a different story, but 12.5, 10.5, 9.5, doesn't really matter. Any tire sucks on ice and only studs are going to help, but still isn't the end all for ice.
CU Boulder Aerospace Engineering